Ascent pannier rack for Downtube IXFS?
 

I've read posts by people who've installed a seat post racks successfully on their Downtube FS (typically Topeak), and also of mtb bikes with the Nashbar Ascent QR (link to picture below). Would anyone have an idea if said Ascent rack with appropriate panniers would work for the Downtube IXFS? Requirements-wise: commuter, short trips including grocery, may need to lug notebook computer.

http://www.nashbar.com/profile.cfm?c...All%20Products

Thanks!