when you buy cheap ebay components, you will get cheap ebay sound.
if you think a pyramid amp sounds great, you should go out and buy xplod audio from sony.
there's not-so-well-known, companies out there that make fairly good sounding gear that doesn't cost much $$$ but a lot better than the cheap-cheap crap made with cheap parts,
gear like:
CDT audio component speakers,
Hercules amps,
Image Dynamics subs
and finally, the rule of thumb for all audio setups:
GET A GOOD HEADUNIT!!!!! you want a good quality SOURCE of sound for your system regardless of what speakers and amps you get.