is it worthit to upgrade my supra with stock turbo?

[fantasma87]

my fantasma it`s a 87 supra with stock turbo, i bought already some upgrades for it, 550 injectors, walbro 255 pump, light flywheel, fuel regulator, aftermarket intercooler, arp studs, and a few more things. my question is that if it`s worth it to leave the stock turbo or should i get a bigger kit? my plans for now its to put my supra to respond realy nice when i step on the gas. i was looking at some turbo kits on ebay and most of them have a t04 turbo with the manifold. they sell them for around $600. please let me know if its a good idea. thank you . Q