Is it possible to have a street legal build to weekend AND race?

[Babu]

So I'm not worried about being competitive at all, just looking to have a good time on track, and on weekends. Also before comments start piling in, 'just get seat time', I know, preaching to the choir but I have some money to spend on this and I'd like something a bit more sporty than stock engine on the miata.

So are there any clubs in the mid-Atlantic with more open classes that would allow me to slowly build out this car over a few years? The suspension on it now is shot, so I'll be starting with spings/ and struts in a few months. Unless I keep it stock this will already class me out of our Showroom Stock Miata class ( NA miata's actually stock + roll bar, very, very cheap) which I was interested in.
Nox VidMate Mobdro

Beyond that, over time, I very much plan to ruin this car by putting in an ls1/ls3, upgraded drive train etc. I don't necessarily want to have to buy parts to class into 1 series, which I might be leaving in a few years. However, as you can tell I'm pretty novice, have no real clear idea how that would evolve over years of racing.

I'm ranting and haven't had coffee. What do folks think about maintaining a street legal build and what series should I look at.