I think the Chump series is a great deal. We have done double 7 hour enduros, Were about to do a 14 hour endurance at Sebring.. And last year we did a 24 hour even at PBIR.
Like Loren said its the cheapest way to go, Plus you have a team to support the car. So if it needs work and to split up the bills. IE fuel to get to the race etc.
Chump also will let SPec E30 and Miatas run in a non compete class.
Lemons is also fun but there still is more contact and bad drivers in that series.