What to look for?

90% of all my LF photos are taken with front rise and/or shift only. The rest has front swing; for some reason I very rarely use front tilt (poosibly because my first LF camera didn't have it - in a practical form, at least),

Most 150mm lenses are cheap and easily available. Start with - well, just about anything. I've used Schneider Symmar and Xenar, Voigtländer Heliar and APO-Lanthar, as well as a Rodenstock Eurygon 135mm and a Zeiss Planar 135mm. With the exception of the Eurygon they are all very good to great. The Xenar (and other Tessar-type lenses - just ask us which they are) have slightly less coverage than the other types.

My suggestion for a second lens would be something a little wider without breaking the bank: A 120mm Angulon (not Super-Angulon). Barely covers 5x7", but plenty of coverage for 4x5". And at f:6.8 they are a lot brighter than the 120/8 S-A. The 110mm Super Symmar is a great lens, but I haven't needed one enough to buy one at the prices they usually get.

To go wider than 120mm gets expensive, unless you settle for less coverage. The 90/6.8 Angulon is usable, but limited. I'd go for a 90/8 S-A instead (I have both).

This is a case of "six of one, and a half dozen of the other" in opinions, which is a good thing. Some prefer view/monorail cameras and some prefer field cameras. That's just how it is. If you haven't thoroughly read about what the movements of a monorail camera can do, then interpret the differences with the fewer movements available in the field camera, you'd be doing yourself a great injustice.

I learned on a monorail, bought one, and will keep it. I would also like to have a field camera for the conveniences in the field. A friend of mine is the opposite: started with a field camera and now wants a monorail as well. If it were possible to have it all (within budget - let's not go into the Toyo VX125 or the Ebony's), I would love it!!!

S