If you're open to suggestions, Getting a Honda 350 and racing it in V1 and V2 would probably be your best bet. The bike is relatively cheap to build/maintain and race and you'll be on the track with some great people to learn from.
Hmmm, for a new racer I think that some early success (not being in last place all the time) is important. It is also better to race in a class that has a top-end advantage in the combined race, i.e with the other classes that run in the race. You can make up time on the straights, some of the guys who have responded will be blindingly faster than you on the tracks they know around corners. For example, Formula RD sounds attractive cost wise, but the guys and gals in that class are super fast. V-2 is ok but you have some really fast bikes in another class that run that race, and they will fly by you intimdatingly on the straights unless you have a TD-3 (heh, heh, heh). I think I'd feel most comfortable on a Formula 500 bike, you have those fast Formula RD folks that bump up into the Class and race, but they are a little down on power so even a novice can keep some of them (only some) in your sights. Heck, at the GNF (in F-500) there was a novice racer on an H-1 Kawasaki that held three or four of us up for at least three laps by just whacking the throttle while exiting the turns and running 10-20 MPH faster on the straights. I run 2-strokes, but unless you are a pretty good mechanic I'd run a four stroke.
I don't have to worry who races V1 and V2 since I only race in LWC and MWC. I'm just trying to crowd Footwork and Vintage777's classes.