Single seater prospects.

[Sparkkadian]

Hi im new to the forum, sorry if ive posted this in the wrong section.

Im looking into the possibility of getting a single seater race car for track days, the problem for me is generally the complete cars ive seen for sale (ex formula renault, dallara, formula jedi etc) are too expensive for what i can afford, however i have seen here and there complete chassis for cheap which just need engine and drive train.

As im only wanting one for fun on track days, i was thinking of going for something like the latter as a project. So far i havent found much, can anyone advise me if there are companies that supply parts to build one up from a chassis? Or any type of complete single seater cars that arnt so high end? Any help would be great thanks.