Is that one eheim pro or two of the pros. Although it is a bigger filter, it is only one filter so if the filter should malfuntion in any way then the life support system for the fish will have shut down completly. In that case it would be better to have two filters so if one does happen to go down, then the fish will still have one filter on the system for them. If the choice is to only have one eheim pro or two eheim classics then I would have to say go with the eheim classics for this reason. If you put two eheim pros or a smaller version of the same then I would opt for that.
I have a 2215 on my 46g bow. It's doing a nice job and is quiet - circulation seems unaffected even though I had to throw a linen dish towel in the top to filter out some dying green algae (Euglenoids) after a blackout period.
RE: F&S sale - make sure they aren't backordered (mine came from BigAls 'cause of this), and be sure to look into whether or not you want the media, valves kit (you at least want the valves, trust me).
Get the pro 2026 very nice filter. You may also want to look into a Rena Filstar XP4 very nice filter with lots of capabilities and a lot cheaper than the eheim.