Would It be possible to run a smaller turbo like a greddy t78 and then a larger one like a hks gt3037 or a greddy t88h to cut back on lag for a twin turbo supra but still keep the high power.

whoa buddy!!! a t78 is no where near small. the t88 does take a while to come to speed, but a t78 will just get in the way. i'd look for a combination of cams that offer all motor power between 3-3500 rpm. get a greddy 18g for low rpms to the all motor power band, then switch to the t88. i hope your ready to spend some money...