To test a BES you need the SRP key. You should have gotten this from RIM with the CD/Download. The SRP is a unique key that validates you on the RIM network. Without it, the BES will not run.

If you plan on using WiFi, you will need the BlackBerry 7270. The 7270 is the only WiFi enabled device. The rest use carrier networks (i.e. GPRS, CDMA, iDEN).