The 2 castable resins that formlabs sells actually perform quite well in both normal and stone-in-place casting. My favorite is the purple ‘castable wax’. The blue ‘castable wax 40’ is really waxy, and deforms easily (it’s 40% after all), so I don’t use it all that often, but it still casts well.
Formlabs has burnout schedules listed on their site for each of their castable resins.
I do second the recommendation to add sprues to the model, however depending on the complexity of the piece you’re printing, it could make removing all the support material an extra pain in the rear.
As far as spruing, gently scuffing your attachment points aids in adhesion, but the best thing to do is plan out your spruing so that you limit how much handling you have to do. Sometimes the sprues attach nice and strong, and other times they pop off with just a bump. It really just takes a bit of trial and error to discover what you can get away with. It also, annoyingly, changes with each resin.
As far as non-Formlabs resins you can use with your Elegoo, I recommend pretty much any castable resin from PowerResins. The dark has incredible accuracy (to the point where you can actually see each pixel from the lcd screen in the model), but doesn’t cast quite as well as the others. Our workhorse is currently their ‘Wax’ resin. Not quite as good at sharp detail, but prints nicely, is pretty easy to work with as far as spruing, and casts wonderfully.