If you know how to tune your own bow or know a pro shop that will tune a bow you bought elsewhere for you, than ebay or any place will be fine.

I would reccomend buying one from a pro shop, they will set the bow up for you, there are an awful lot of reasonably priced good bows out there, I just got a new one myself, a Browning Ambush, it fits me to a tee and shoots great. Find a bow that feels good to you, you will always shoot a comfortable bow better than any other bow on the market.