Help me pick a wastegate

[Mitchocalypse]

I would like some input as to which wastegate would be better for my setup. I want it to be as reliable as possible but not overkill. I want to order everything ASAP so a quick response + reason would be all I'm looking for. (I really don't know how to pick a specific wastegate.)

Turbo would be the ZN Performance garrett T04Z, with a 1.00 turbine a/r.
Long runner tubular manifold that comes with the kit,
3.5 or 3 inch downpipe (I'm not entirely sure.)

Anyways, the kit normally comes with the synapse 50mm wastegate, however i much prefer TiAL over synapse so that leaves us with the MV-R (44mm) or the V60 (60mm).

My goal is to make 500whp on approx. 21 psi of boost. If you need more info, I will gladly provide it.

Thanks!