OK, so to be honest with you, I am not sure if you are buying the bw's used or getting a great deal but you can do better, how about you list a budget and we let you know what we think would sound good, then you can demo a few things go and listen for yourself and have a better system.. I am not a fan of the 28649 tweeter that comes in them, first I hae heard issues with them cooking, and second they don't sound good to me... Just not worth the money, there is better sound out there for less money...
Now for a sub, yes I would get one with them speakers and with almost any speaker made, there are very few that I can think of that satisfy my needs for low end...
DO you also need a reciever, is this for music only, what are your cources {cd, ipod, turntable?}