I can help you pm me your goals and max dimensions and the specs on he sub
i can help you as well. i have a 4th order in my truck and it plays stupid low with alot of output. its got amazing sq i actually prefer them to ported boxes. so if space is available i would definitely do all i can to make one. im going to try out a 6th order in the future as well and i can pm how it works out.
sound good man let me know how that 6th works out!