You're shooting strobes so, you'll need a (modern) shutter that has a flash synch connector. The Copal shutter is common and usually, pretty reliable. I don't think I've ever seen one with out synch. So, the way it works with the vast majority of modern lenses is that the lens is really two groups of lenses. One group is screwed into the front of the shutter and the other screws into the back. Usually, the shutter and lens all come together as a unit. In your situation, avoid lenses in barrel - that is, the ones with out a shutter. Also avoid the ones in "DB Mount" this is peculiar to Sinar and not generally useful unless you have a Sinar Shutter thingy.
The lens mounts to a lens board. Generally speaking, you will need a lens board that is specifically made for your camera. A few types/sizes have become defacto standards...but, again you will need the right lens board for your camera. Here's the neat part...only the lens board is specific to the camera...that is, Copal Shutters only come in a few sizes...so, once you have a lens board that fits your camera and has the right sized hole in the middle of it you're set. The copal #0 shutter needs a 35mm hole, Copal #1 needs a 42 mm hole and the big Copal #3 shutter needs a 65mm hole...
My personal preference for "head and shoulders" on 4x5 is 240mm...but, that is just because I happen to have a really nice 240mm f/5.6 lens. Prior to that I used a 210mm lens - which is fine. (caveat: I rarely do tight head and shoulders).
Strobe lighting and exposure basics don't change just because you move from 35mm to 4x5. You may want to give consideration to fact that you'll e using a longer focal length lens on 4x5 than you do with 35mm...the effect that the longer focal length lens has on depth of field may entice you to use a smaller aperture with 4x5 than you are used to with small format.
Modern Copal #0 shutters (150mm lens) have the usual shutter speed progression that you are accustomed to - except that 500 is the highest speed. Copal #1 shutters (210mm lenses) go to...hmmm, is is 400? Anyway, the progression is the same as you are used to but the highest speed will be less than 500. Sometimes much less (Copal #3 only go to 125). The Copal Press shutter also stops at 125). In anycase, you will likely find little use for the highest speeds.
Film holders and hand loaded individual sheets are the order of the day. As Brian said above, the packets, called "ready loads" or "quick loads" are all gone now.
All of these questions and more are easier to demonstrate than to write about (well for me anyway). You may wish to find somebody nearby to help you understand how this all works - it is not complicated...but, it is a little different from 35mm...to that end, I also suggest that you take a moment to add your location to your profile info. It helps in so many ways.
Tripods and heads are too personal a matter for me to comment on. To each his own I say. Try a bunch and figure out what works for you.
Last edited by BradS; 12-23-2012 at 10:08 PM. Click to view previous post history.