since you're comfortable welding, I would suggest for you to move the mounts and mount up some supra calipers and discs
there is a supra TT relocation bracket out for the camry right now- it's just a bracket to move the calipers out so that the supra TT rotor will fit, but it does not allow the use of the supra calipers though. that, and if you're going to go through the trouble of finding a set of the brackets or making your own, you may as well just do the full thing with your 3" welder
on that note, post some pics! most specifically- of the mounts and how you made them!