Bolt in cages or have one built?

[George3]

Just for clarification purposes, I'm assuming you mean a full roll cage from rear to front of the cabin... and not a roll bar which is just behind the front seats and does not extend forward to the windsheild. 

Assuming it's the latter, then most aftermarket roll bars are sufficient for DE use.  DAS, Techquipment, etc.  If the car is being used for racing, then a full roll cage is a must. 

I have a full cage in my car that is a hybrid bolted and welded cage.  It is incredible how this stiffened up the car when the full cage was installed.  The custom fully welded cage is the cadillac, while the bolt-in cages at least provide more roll over protection than just the rear mounted roll bar.

Depends what the intended use for the car is.  Either way, folks should stay away from harness bars, as they provide no roll over protection whatsoever.