For now I will use the 1600 DP Type 1 engine. It runs great and has proven reliable although underpowered.
I have to put a new trans in it. The cheapest route is replace it with a swing axle. Ideally I would swap in an IRS trans.
I do need to swap in disc brakes at least on the front.
I like the idea of the open wheel concept. I think that would look really cool.
I am thinking a DE/Autocross car since I am doing this just for fun. No rules is always more fun.