Yeah, if you don't need a 34 tooth cassette, just get a new 9 speed cassette with less of a range. I have a 9 speed cassette that is 12-28, they also make smaller big sprockets. It doesn't matter if it is a "road" or "mountain" cassette, they are the same, just a marketing tool. Typically mountain cassettes have a bigger large sprocket, like 32 or 34 tooth, but how they are made and compatibility are the same.
A few choices for you on eBay:
SRAM 12-23
SRAM 12-26
Shimano 12-27
It would be easier and cheaper to just get a tighter 9 speed cassette. You might need to adjust your chain, take some links out and readjust your rear derailleur.