Expanding upon some of the good advice already given:
Steve is right. Many people give advice that doesn’t go past “I have camera/lens/meter XYZ and they are all the greatest in the world”. That’s no more than subjective opinion, usually based upon limited experience (like most of us have). What you really need to ask yourself is “does my current equipment serve my needs”. Sounds like you haven’t really come to grips with that question yet. Spending money just for the sake of different equipment will not do much except empty your pocket. Lets take a look at a few of your items.
Camera: I have a Graphic View 1. It was my first LF camera, and I’ve used it for a year now (limited experience) in windy Kansas and it has served my needs without fail. My only quibble with it is that the front rise doesn’t have a positive lock and sometimes it will fall after being set. A minor inconvenience in my view.
Is a new camera better? New cameras typically have a better way of tilting/swinging and locking. They typically have scales marked on the rail and swings so one can actually have a measurement of the extension/swing/tilt/rise/fall. I have yet to feel deprived for lack of these conveniences. If I need to know bellows extension for exposure adjustment, a handy simple tape measure works just fine. I don’t know why its necessary to know how much tilt/swing is applied. I haven’t mis-focused yet using the ground glass. A new camera may have a longer rail for more extension. Whether this is needed depends on your lenses which depend on the focal lengths needed for your work.
Second camera question: Does the monorail work for me or is a field camera needed? Again, this must be answered based upon experience and need. Fully evaluate this question in light of your needs as the work dictates them. Personally, I have not felt hindered or inconvenienced by the 4x5 monorail. In the 8x10 world, it’s a whole different story and I use a field-style camera. An 8x10 monorail would be wholly inconvenient for my needs (and I’m not about to put up caring for the pack mule to carry it!).
Lenses: This is the part I see as being worthwhile to spend some money on. Lenses are always transferable between cameras. Buy a new one, of a focal length you are sure to always need, and see if it makes a noticeable difference in your prints. The print is the only real measure.
Next question; do the focal lengths I have meet my needs? If not, add another lens, new/classic depending upon how you feel about the new lens. Currently, all my lenses are classics (read old). No one has yet to be able to point out where a new lens would make a difference in my prints (limited experience again). Remember, Adams, Weston, and the other past Greats used lenses that are obsolete by current manufacturing standards. (Same thing can be said about their cameras.) Several of the current Greats still use the classic lenses.
Enlarger: I used an Omega for several years and thought they were the last word until LF brought a Beseler 45 MX into the house. Now I believe the Beseler is an overall better design. Firstly, one doesn’t need the Omega lens cones for each lens focal length. Secondly, I think the Beseler has better adjustments and a better system for holding filters. Check your alignment as Don suggested before spending any money on a lens. I would try a different camera lens way before switching enlarger lenses. For whatever its worth, Ansel used a Beseler.
Meter: The Pentax 1/21 is a long-established standard. If batteries for it have become a problem, then upgrading may be justified. Don’t be fooled into believing the digital meter is better than the analog. Most people base this argument on the “digital must be better because its digital” theory. This is not true. My opinion is that the digital meters have too many features that are non-useful. An analog meter is still the easiest to read and interpret.
Sorry for the long-winded reply, but I totally appreciate your questions. Being relatively new to LF myself, I have pondered the same issues.