Competition Engineering has a complete frme kit that you could use . Make sure everything is really square when you install your subframe , take your time measure corner to corner to be exact . I would use a tig to do all the welding .There are some really nice coil over kits out there , with a complete subframe welded in your car you would only have to put a roll-cage in as extra measure . But it would stiffen thing's up a bit.