Just keep in mind a full non genuine VRS would be roughly $350 where as you may pay that just for a genuine head gasket.
Currently I have a 4V 351 GT motor that was rebuilt with non genuine gaskets, 500+ horsepower and 11-1 compression no problems, I also have a 302 Clevo rebuilt with non genuine gaskets that regularly revs above 7000rpm with no issues at all, my GQ TB42 was rebuilt with non genuine gaskets over 50,000k's ago and it's like a rolls royce. Keep in mind, unless you have the engine rebuilt at a dealer, and specifically request genuine parts only they will sometimes substitute genuine parts for aftermarket, as we have supplied dealers with aftermarket parts. We also supply 5 workshops with gaskets, so you're fairly safe.
Make sure your head machined, your block is decked, or al least has a straight edge along it to make sure it's true, and always replace head bolts when you remove an alloy head.

