What Tamashii stands are best for a Super Robot Chogokin? I googled it but could not find a good answer.
Theoretically any Tamashii Stage but they do have the Act 5 specifically for robots.
Amazon has sets of 3 for around $18.
Which SRC do you plan on using the stand for? Tamashii Stage Act 5s can barely hold GaoGaiGar up, and near useless for GaoFighGar and Genesic.
For those three, better get a Trident.
Alteisen and Zeorymer are a bit flimsy too.
I would avoid displaying SRCs on stands, suspended in the air. They are weighted to be bottom heavy so that they can balance without a stand. The heavy legs would mean that the hips will be under a lot of stress if propped on a stand. Granted, we haven't seen something as disastrous as Max Factory's Genesic GaoGaiGar dropping its legs but who knows what will happen in the long run.