Track versus strip racing..opinions

I know there has been a lot of good discussions on modifications for strip racing, but what about mod's for track racing? I've been asked to join a couple of car clubs so its time to start thinking about mods for the track. The "beautification" phase is almost done and I would rather start to divert funds on the mechanical spectrum.
To start, I know we are a little "chubby"...LOL.......and we tend to get into a oversteer condition on cornering....so the first mod should be the tires. I was thinking on the rear at least a 305 upgrade. We should have an advantage on the straights, but the corners are of concern.
While trying to keep the HC "street legal", can you think of anything else?
Your thoughts, experiences and opinions would be appreciated. Any recommendations on specific tires and manufactures would be helpful.