If you're not going for an upgraded CT-26, you're going to need either a big T3 footprint turbo and manifold (Garrett GT35R, Borg S200, Precision 3431E, 6031, and I think you can get a T3 housing for a Holset HX35) or T4 manifold and T4 based turbo (S300, 35R, GT40, PT5862, etc.)