First, there's not much out there at this point in the year. That being said, here are a few options I've seen just from a quick glance at my league....
Snyder is not a terrible option. Low average, high power. Similar to Buck, but not as extreme.
Ryan Hanigan might be out there. He doesn't play every day (more or less splits time with Ramon Hernandez), but he hits a few HR (around 5 a year for his career) and should be able to put up a decent AVG (somewhere in the 260-270 range maybe, though with so few ABs AVG is really a crapshoot). Hanigan does have a nice 1:1 K:BB ratio so far this year though.
Nick Hundley is currently on the DL, but he should be coming off next week sometime. He'll probably hit somewhere in the .240-.250 range, and he's hit 8 HR in ~250 AB the past 2 years. Not pretty, but at least it's something.
Then you've got Devin Mesoraco, who's currently in AAA for the Reds. Dunno when he'll be up, but he currently has an .861 OPS in AAA with 5 HR and 4 2B in 166 AB. And he's only 22, which is nice.
If you're in a daily league, you could also try rotating catchers every day, and using the guy who has the best matchup/ is hot at that time. There are some decent-hitting catchers that are backups on their own team (David Ross comes to mind first; Ronny Paulino and Brayan Pena are other ok hitters). If you have the time, you could probably do ok by using some of these backup catchers on days when they are playing.
None of the options are great; there are a couple out there though.....