what is the best cage you can buy that is prefab?
it doesnt have to be welded i can do that

 

Autopower.

Edit: personally I wouldint even consider putting a cage in unless im at the track atleast once a month or if my car is going faster that 11.99 in the 1/4mile. I see it as more of a safety hazzard unless its well padded and you are always wearing a helmet.

 

You might also want to check out http://www.kirkracing.com, they have some nice roll bars there. They have bolt in kits and also full roll cages.

 

Too broad of a question. Be more specific.