So, I have a good working system. It is a 15" type R alpine sub and it is in a custom ported box with a Brutus amp with a max output of 1200 watts. I want to buy an identical type R and a better amp and then build a custom box for them. What I need help with is what kind of amp I should get(keep in mind I don't want to spend a ton), and I need to know what kind of box I should make.