I don't have the vx nano, but I do have an m905 mx anywhere mouse.
They seem to be very similar in shape and size(going by pictures), though the m905 has the two additional buttons in a better place(near the left thumb, rather than near the forefinger). It also uses two AA batteries, though one can be used instead. However, it's been replaced by the anywhere 2 mouse, which I'm not a fan of, since it uses a non replaceable battery. There was something else as well, but I can't remember it at the moment.
Looking at current mice I can buy, I'd go with the m560; it's very similar to the anywhere mouse, though it uses only one battery. Another alternative is the m545; it has a smaller receiver compared to the m560 & anywhere mice, although I wouldn't call those large.
Unfortunately you can't use the m325 receiver for the vx revolution(it came out about 12 months before the unfying concept apparently).