What all do you guys think in order is the most important pieces to upgrade to a 5.1 system? Right now I have a pair of Ascend 340 SE mains and and a Yamaha R-V1600. What is the most important thing to uprgrade next? Sub? Center channel? surrounds? For the subI am planning on getting a HSU VTF-3 MKIII and an Ascend 340 center channel and Ascend 170 SE's for surrounds. And also is it recommended to have a center channel and no surrounds or should I just wait to i have both to hook them up? Say one day if I have a 3.1 system(mains, sub. center) would the receiver decode the 5.1 information and convert it to 3.1? Just trying to get some feedback on how I should build my system.