Rockerverb 50 for Bleed American Sounds?

[PolymerBen]

SO I recently purchased a Rockerverb 50 combo because i was just blown away by my inital impressions of the amp and am now in the studio recording. I am looking for a very specific guitar sound similar to Jimmy Eat World's Bleed American Track 1. I have been getting decent distortion with a strong mid-range that i think is fairly similar to the sound from this album but it's not quite there. I'm wondering if maybe the speakers in the RV 50 combo are not what I'm looking for. Can anyone tell me if there is another cab that I might try the RV 50 through to get a (for lack of a better word) "tighter" sound?

Also, I have read on some other forums that Jimmy Eat World used an Orange 120 Head through a Marshall Cab. I was wondering if anyone might be able to explain the differences between the 120 Series and the RV series