As no one else has jumped in I will try and give you some ideas but my experience of different resins is limited.
First off, the bewildering descriptions for the resins:
ABS-Like: Stronger but still quite brittle
Rapid: Cures at shorter exposure settings
Tough: Less brittle and as suggested stronger. Can often be machined
Resistant: No idea
So lots of different resins which in the current Covid crisis are extremely hard to source. The Anycubic Basic Grey is I think ABS-Like and is my first choice of resin. Unfortunately it has been out of stock in the Grey form for a while (unless you are prepared to pay extra to buy the 500ml bottles) and I have recently had to use White. Elegoo do a standard and an ABS-Like version. When I could not get my preferred Anycubic Grey I did buy a couple of bottles of Elegoo ABS_Like. It printed OK but I did not like it as moulding seemed to remain sticky on post curing and the uncured resin is quite runny and needed constant stirring to keep it mixed (not possible on a big print job). If you want a tough resin the one everyone raves over is Siraya Tech Blu. I suspect this is the one worth looking into for wheels based on reviews.
Warping seems to occur when the resin shrinks slightly. Different resins have different shrinkage rates and this can also be affected by the exposure settings used during printing. Some shapes it is almost impossible to stop warping however there are a couple of dodges that can be used to reduce this:
Place warped item in near boiling water, straighten, and put under cold tap. This seems to remove a lot of the stresses that cause the warping.
Add to the model various cross bars that are left in place until the model has cured, then cut them off.
Leave the model on the support structure to cure.
I have used all three at various times. For wagon bodies I would try a simple open box with the Anycubic resin and see how it reacts.
I have an Anycubic Photon and there are a lot of similarities to the Elegoo Mars including some shared components. I have recently replaced my LCD screen with an Elegoo one and likewise am now using Elegoo FEP sheets in my Photon. Elegoo parts are usually cheaper.
The best advice I can give you is to join the relevant owners' groups on Facebook. A lot of people are present on both the Photon and the Mars groups. In addition to problem solving they are often trying new resins out and reporting back.