I wouldn’t even consider a bigger turbo without pistons, rods, arp rod bolts and arp head bolts personally. At 400hp+ hp, a single mass conversion and oil pump balance shaft delete is probably wise also. That amount of grunt will kill off stock engine mounts pretty quickly as well.
Something to consider. At your current power level, you need to aim for +100hp at least to justify the cost and really feel the difference. If you only want +50, not worth it imo. The sacrifices in refinement, turbo lag and drivability just aren’t worth it, imo, unless going for the big guns.
Just my thoughts having been down this road many times