I was looking for a simple a comparison of iPad models but could not find one so I created one by gleaning information from various sites. I cannot vouch for the accuracy but it should be pretty close.
iPAD2 Models
Model Name Model Number RAM Color WIFI 3G Type Carrier Notes
MC755LL/A 2340071 16GB Black Yes Yes CDMA Verizon
MC763LL/A 2340502 32GB Black Yes Yes CDMA Verizon
MC764LL/A 2340557 64GB Black Yes Yes CDMA Verizon
MC769LL/A 1945531 16GB Black Yes No
MC770LL/A 2339322 32GB Black Yes No
MC773LL/A 1918159 16GB Black Yes Yes GSM AT&T
MC774LL/A 1918229 32GB Black Yes Yes GSM AT&T
MC775LL/A 1918265 64GB Black Yes Yes GSM AT&T
MC916LL/A 1945674 64GB Black Yes No This one seems out of sequence.
MC979LL/A 1945595 16GB White Yes No
MC980LL/A 2339386 32GB White Yes No
MC981LL/A 2339877 64GB White Yes No
MC982LL/A 2339904 16GB White Yes Yes GSM AT&T
MC983LL/A 2339986 32GB White Yes Yes GSM AT&T
MC984LL/A 2340017 64GB White Yes Yes GSM AT&T
MC985LL/A 2341061 16GB White Yes Yes CDMA Verizon
MC986LL/A 2340478 32GB White Yes Yes CDMA Verizon
MC987LL/A 2340487 64GB White Yes Yes CDMA Verizon