250whp should be attainable with that setup, absolutely.

I would go with a Revhard manifold over Drag, as the Drags wastegate placement over 1 runner can lead to spiking issues with large exhausts.

You may be able to get away with the stock fuel pump with the AEM, you should look into that.

Id go with ACT, personally over Clutchmasters.

As for the FMIC, I dont know how much money you want to spend...a PWR or Precision would be nice, but youll also be fine with a used Drag or RH IC that can be had for fairly cheap from guys who are going big.

2.25" IC piping is fine. Vacuum manifold is nice, but not necessary.
You'll also need a dumptube for the wastegate, or have one welded into the downpipe.

If I was to piece together a kit, I would without question spring for an equal length mani like Lovefab or Full-Race. If Im going to go to all the trouble of piecing together a kit, may as well make it the most efficient possible. All the things you listed can pretty much be purchased as a Drag kit, so I dont really see the benefit of buying everything seperately other than making more of a headache for yourself.