SHWEET BIKE FISHERMAN!!!!
Like you, I was trying to make wise decisions about where I spent my money. Knowing what I know now, there are a few things that I would have done differently, but not many. Starting with a good bike is one of the keys. By the looks of it, you're already there.
when it came time to buy an engine, I came to the conclusion that it's pretty much a craps shoot and I was right. If you start with a company with a good reputation, it helps. Customer service is key. I bought several engines from Gas Bike. net and, while I've never gotten what I paid for, I've never gotten less either. If that makes any sense. Even "buying the better engine kit", we've still had a few things that needed addressing. These were all 2-stroke kits by the way. Now I see that Gas bike has a 4-stroke kit for under $200 (on sale now). I'm tempted to try one of them and, with a nice bike like yours, it would make for a great ride, unless you're going for that "looks like a motorcycle engine in there" kind of thing. That's why I've got 2-strokers.
The best thing I could say is figure out what you want to do with your bike so far as any other modifications and do them, while you research which engine kit is best for you. I changed my bike drastically while I was trying to decide which engine kit to buy. Now, I've got a bike that I love to ride and I'm happy with the engine kit that I've got on it. I hope this helps.