I think what Curtis is trying to say (besides the brand I sell is best) is you can use any chassis as long as it works for you.
An awful lot depends on your budget and abilities, probably your best bet is to buy a well sorted package that’s been competitive at your track. Alternatively you could go with whatever your local shop sells and supports new.
All the manufacturers should have something that will work for World Formula by now (it’s been around like 10 years)….
It’s great to see that grid at my former track, just wish I could be there running with you guys not that it’s caught on.