If not for the architecture pix, I would recommend a Crown Graphic, which is cheap and folds down into a nice package. However, there are still the Graphic Views, which are nice and cheap, and also light. It's the glass that matters most, a camera is just a light tight box, and there are lots of cheap 4x5s that are plenty good, but I find these to be one of the best bangs for the buck, because they are actually reasonably well built. Get one without a Graflok back if you really want to get one cheaply. There are three models: 1. GV, which has a short rail, tilts from the bases of the standards, and a spring back, 2. the early GVII, which has a longer rail, movements from the center of the standards, and a spring back, and 3. the later GVII, which is the same as the early GVII, but with a Graflok back. Make sure the rail clamp is included if you get a Graphic View. It is a combination rail clamp and tripod head with a long arm to loosen or lock the tilt.
Any large format lens from a well-known maker, and many from not-so-well-known makers will be good. The big and common names are Fuji, Rodenstock, Nikkor, Schneider, and Kodak. Calumets and Sinars are relabeled Rodenstocks, and Linhofs are relabeled Schneiders, to my knowledge. IMO, the thing to do is assume that all large format lenses will be more than high enough quality, and just research the coverage of the lens, so you can see how much shift they will allow you. The standard two-lens beginner kit that offers a ton of versatility would be a 210 convertible and a 90. Get older glass and smaller max. aperture models, such as 90mm f/8 or 210mm f/6.8 (instead of f/5.6 or f/4.5 models) to save money. If pinching every penny is not necessary, very nice 210s are so common and are being dropped like bad habits by many students and professionals who bought them in the '80s and '90s. These are usually multicoated glass, more modern shutters, and usually less beat up.
As for accessories...IMO, a good tripod comes first. A gnarly used Bogen 3051 or 3036 will be more than enough for the camera, and are usually under 200 USD used in nice shape with a nice 3047 head and quick release plate included. You could get by with something lighter, like a 3021, but not for much less money. It will work fine, but heavier does = better, in general. If you are going to walk or hike a lot with it, that's another (and much more expensive) story. Also, these lighter tripods more often do not come with the nicer 3047-type heads that are usually on the two big ones I mentioned above. I would invest in the purpose-made $35 strap for the tripod. I was reluctant to spend so much a a strap of material, but after much use, I feel that it was a worthwhile purchase. I happen to have, like, and know Bogens, but I am sure other brands have comparable models that you can find used.
After that, a decent loupe, preferably with squared off corners. (I need to get on the ball in this dept., as I have always used crummy plastic $5 loupes. I borrowed a nice loupe once and DANG! It was NICE!)
A lightweight black coat (I have several that I use) has always worked well as a focusing cloth for me. When carrying heavy crap, things that have multiple uses are your friends! If this doesn't work for you, then a focusing cloth is the next thing I would suggest. If you are going to bite the bullet and buy one, I will say that the ones that are silver or white on one side are very very nice to have in hot weather!
Of course, a light meter. Budget aside, the one you should get depends on how close to your subjects you will be and whether you will ever use flash. I have a preference for the Sekonic Studio Incident Meter and the Pentax Digital Spotmeter or Spotmeter V. Whenever possible, I use both. (I have always borrowed a meter for the rare occasions when I use studio flash. With speedlites, I use the scale on the flash or a guide number.) There are some very reasonable combined incident/flash/reflected meters out there, and there are also spot attachments, or more expensive models that have a built-in spot meter as well.
An extra bellows and a frame to use it as a lens hood can't hurt.
If you get a GV, try to get one with an original case. They are quite nice and easy to carry, and are designed to accept a strap as well. You can also get the cameras into a backpack without too much hassle.
Film holders can be hit or miss used, but usually hit. I have had about a 80% success rate with the holders that have come with my cameras or been given to me. Test them all in daylight with a fast film before using them for anything super important. I save the slides from the bad ones in case I lose one from a good holder, or get some holders in the future with a missing slide, and then I chuck the leaky bodies in the trash 'cause they are so cheap. Even with my good holders, I shield them from light as much as possible when shooting. How many holders you need depends on you. Personally, I have 40 holders, which is overkill, but they all just came to me through various camera purchases and gifts. I usually don't use any more than 25 sheets at a time. I would say that 13 holders is a good number to start with, as you can load a whole 25-sheet package of film that way. If you have money to spend on it, I cannot speak highly enough of the Fuji Quickload system. No dust, no light leaks, huge weight reduction, less chance of user error, etc. I don't use them all the time, but when I do, I find myself wanting to use nothing but Quickloads in the future!
So, IMO, the musts: tripod, something to use as a focusing cloth, good film holders, case, cable release.
IMO, the "nice to haves": loupe, light meter, backpack, Quickloads, lens shade, "actual" dark cloth, tripod strap, cable release for each lens.
Wow. This got horribly LONG. Sorry...