Alice,
I read your post and I too need zip ups because I can't tie a boot. I don't want to sound like a L.L.Bean commercial but here's one suggestion.
Check these out. My wife bought me the mens version a few years ago and loved them so much she got a pair. Very comfortable and long wearing.
http://www.llbean.com/llb/shop/57134...069-ppxs&dds=y
Good hunting...