Truck Cap/campershell

Looking for a truck cap to fit a 2001 tacoma x-cab, 4 cyl
~any reccomendations on fiberglass cap that works well and doesn't weigh too much
~cost is a big issue, any special web sites that offer a deal on used caps? (can't find one on ebay yet)
~anybody have experience with camper tops/caps on tacos running a 2.7 4cyl?

thanks, jpearceb