Hi Richie,
There are a lot of e-Bay books out there that explain all about sourcing goods, drop shipping, etc.
Take a look at How to Buy, Sell, and Profit on eBay: Kick-Start Your Home-Based Business in Just Thirty Days by Adam Ginsberg. It's a very easy read (even if he is a little too positive about e-Bay !).
I did some investigations into setting up an e-Bay business recently, but have yet to get it really started. Best of luck dealing with the Irish Postal service !