Most pro porters (Carpenter, KWS, Lee Shierts, Lazer, Comp CNC) will open up the port volume. The reduced choke velocity port is an alternate, less common method. I picked up 8hp with mild porting, a race cam, 14:1 CR, and .026" squish. I have a small-port head now on my turbo, built by Ryan Kallina, but haven't tested it back-to-back yet. The stock valves are fine for normally aspirated motors. Swap out the Ti ex valves for turbo or heavy nitrous use, too much heat.
If you plan to use the motor at high rpm ranges, I would highly suggest a set of stiffer valve springs. Not only will the head perform better with more accurate valve closing, but you will help to prevent valve spring retainer failure. The Carpenter 62lb single springs are $150 from Schnitz Racing. The APEs are a bit lighter weight, double spring, and around the same price from APE.