Eric,
I would suggest that you try soloII, even though it's "too strict". There's no comparison to how much fun it actually is, as long as you don't expect to win! And the cost is quite low compared to other forms of motorsport. You'll learn a lot of car control (not street driving, this is completely different). Swapping ends is a bit safer in a wide open parking lot at 50km/h as opposed to on the racetrack at 120+km/h...
As for where to compete, I would suggest soloI. You can read up on it at:
http://www.soloontario.comIt's basically like soloII, one car at a time, but it's held on a racetrack instead of a parking lot. The ontario series runs at Shannonville and Mosport for the most part. I would be going down this route myself, but my plans are a bit different this summer.
Read up on the rules at the above website. They also treat modifications a bit differently than SoloII. I think that this might be exactly what you're looking for.
You could also look into road racing in Ontario, but the costs really add up here. Each race is about $400 just to enter. You also need to get a race license in order to compete, and you'll need to purchase some equipment as well. Roll cage, transponder, full racing suit, shoes, helmet, it adds up VERY quickly. Unless I win the lottery, I don't think that I'll be trying this myself.