Spooky, those would work just fine, especially for a snowtrooper or AT-AT Gunner (just might try to score a pair after I get this done with), but this is what is what is asked for from the 501st:
"Boots
For 501st approval:
White or light Gray “moon” boots. These are very hard to find without some kind of decoration on them, but they are out there.
Snowtrooper style Canadian Muk Luks with ALL lace loops and 'D' rings removed may be used if moon boots are unavailable.
For level two certification (if applicable):
White or Light Gray Moon boots, with no exterior markings or fasteners and a serrated sole."
So yes, those might be ok'd, but always try to go with moon boots if you can find them. Here is the full list:
http://www.501st.com/databank/Costuming:TA_AT-AT_driverKeep those links and suggestions coming Spooky, I really appreciate all the opinions I can get. After looking at the picture the 501st uses I would say I am spot on so far!