Get a Peruvian BCC then. They can get up 9-10'. Would take like 9 years but they are the biggest of the boas...not counting anacondas...

Me personally, i prefer nothing over 10-11'. I want stuff that is easily manageable and doesnt need huge caging. While i know people keep retics and burms in 6' caging but for me, i prefer to give my snakes caging where they can stretch out in which is why i am looking at a T65 next year for Caesar. An 8x3 cage is about the biggest i want in caging. If i got something that got 13-16', i'd feel bad cramming them in a cage half their length but thats just me. Plus i dont want to go broke having to feed an army of snakes that eats goats lol.