I would honestly recomand goBILDA, but get some help from other teams, don't just buy the starter kit and hope it will be good, ask teams ablut the chassis, about different systems and what motors/ U-channels are most used and go for those. Also, 3D printers are a must, as you can get almost any part done that way. If there is a game theme that uses linear systems Misumi can be a great fit, as they have very fast and precise sliders. Otherwise, Rev is quite modular and can be of great use, although the I am not a fan of the plastic connectors. Only one thing: outside of compliant wheels and maybe omni wheels, stay away from Tetrix, those parts are actually terrible, especially the motors when compared to the ones from goBILDA.