Build or Buy SE Rank Position tool?

I've played with Trellian's product and some others.  I'm not sure if anyone outside building their own has what I'm looking for.

I essentially want to take a word stem or maybe a location and stem and pull down rankings from Google & Yahoo for the variants.  Here's the trick.  I don't want to do it for a single page, but for the domain.

I'm probably explaining it poorly, so an example:

Search for:
Washington, DC widgets [and permutations]
from gooruze.com [and all subdirectories, not subdomains]
where position = 1-10

Anyone know of anything like that or do I have to build it?  My experience with Trellian and a couple of others was that each page needed its own record and its own keywords.  I can't do that on big sites.