Hmm... wish I could help you out Ace, but I don't know of any way to cross-reference maps by footprint. Some map designers around here will list that info in their description, but that's by no means a universal practice. I think any maps created using Virtualscape will indicate the hex dimensions (length/width) of the map on the actual pdf of the map (at least, mine do), but if you've downloaded the map then you should already have an idea of the footprint anyway.
Anyway, try looking at
Nadi's old site for some really great maps. He's got some really good pics to go with all his maps, so you can easily see if there's anything there that suits your needs. Go quickly though, it looks like he's moving on from Heroscape and the site may not be around too much longer.