Hi guys. I currently have a Cambridge Soundworks amp/sub and 2 aiwa 95W speakers on my setup. I want to avoid purchasing an AV reciever as I am a little tight on money. I found another pair of speakers I want to use on my system. Firstly, should I purchase a separate amp for my aiwas? My audio card can have it's own subwoofer channel, but it is currently being pulled from the standard audio meant for the speakers. Also, what do you guys recommend in terms of amps for my other speakers? I believe they are ~40-50W each.