Which PPC has geo-targeting?

Due to nature of our business it’s pointless to advertise in 2/3 of US states. We serve about 1/3 of US and US only.
In Adwords, Yahoo and Microsoft you can geo-target your ads, and ad groups.
We tried Nextag, Shopzilla, Pricegrabber in a past, but unfortunately seems like those guys simply don’t geo-target. If customers from our served areas clicked the leads sale numbers were really high, but at the same time, we have absolutely no point of paying for a click from Japan or Brazil, that’s going to lead nowhere.
Can you recommend great engines, like Shopzilla, Nextag, Pricegrabber, Amazon, that could geo-target? Maybe these ones can be geo-targeted somehow?
Thanks.

See original post by enc