Track Building Advice

Hey team, the church i go to has gave me the go ahead to design a track, yes you heard it right, the church is building an rc track to go along with their gun range; two of my favorite hobbies and i can do both after church, that being because im handicap, that is what it is for after all. Anyhow i have almost unlimited flat space as for as an rc track goes. I want it to be an oval with an offroad infield so as to accommadate the local oval guys and the offroaders. I want the ability to have pipe "gates" so that cars coming around the oval will be diverted into the infield and back out again as to make an offroad road course and be able to close it back to make an oval track. I wanted to know what my overall dimensions should be. And maybe, if anyone knows, what the maximum distance between offramp to landing ramp on an 8th scale track is and i would like one to be a distance that only a brushless car could make, hehe. My overall dimension that i had tought of was 150'x200' but that may be excessive. Also a suggested number of jumps, whoops, table tops, straights and any other obstacle that you might think of. Im open to all suggestions.