What leader did you use to play as and why switch to Forge? He's an okay leader for teams, definitely tough to win with in 1v1s. Plus, going straight for grizzlies (or any other super unit) is a bad idea, why do people always want the quickest build for it?
For a warthog rush, simply continously make them from the start of the game and build your reactor second or third to research gunner. The heavy supply pads might hault your production temporarily but try to get as many gunner hogs as you can out quickly. I wouldn't advise going for gauss with Forge, Anders can tech to it much quicker and could also make gremlins to stop you. It should be more of an opening harrassing force, giving you time to build tanks/hornets.
You asked for a grizzly build, I'll give you a decent tank/hornet build for team games. HSP, HSP, HSP, HSP, Upgrade base, R, R, VD or AP, Advanced Reactor, Queue Canister or Wingman, recycle single reactor, make another VD or AP, double pump tanks or hornets. It's a pretty popular build, but don't rely on it in 1v1s, it takes some time to get started. You will have an excellent mid game.
GT: bb2010