For a start do you have the large eDGe - 10 inch LCD screen, usually referred to as EE, or the Pocket eDGe - 6 inch ?? LCD screen the PE.
Next does it still have android v1.6 - Dingo - or have you updated it to v2.2 -Ermine? If you have the PE then you can upgrade to a modified version of Ermine that will allow you to access the market.
The limitations of both the EE and PE are the android version and the hardware - the eDGe is not a phone and as such does not have any of the phone hardware. This causes problems when developers have their apps check for phone hardware on install, even if they don't use the hardware, and so will not install even if they will run on android 2.2.
On
http://www.freewarelovers.com/android you will find several versions of most of their listed apps. If the latest doesn't work an earlier version just might.