As always, the news comes from those wonderful lads over at XDA Developers, specifically it looks like Mikeyxda's M6 is the best option out there. According to the post, you should be good to go as long as you have a rooted device with ClockworkMod Recovery, and an ARMv7 processor, which includes most Archos tablets, the Asus Transformer series tablets, and many of the premier handsets from HTC, Motorola, and Samsung going back a couple years.
Mikeyxda's M6 looks like the best option as it includes offline dictation, as well as most other options, but there are a few different options to try out. Each comes in an easy-to-flash zip file that shouldn't need any extra permission changes or anything like that. So, if you're comfortable with CWM, you should be all set.
If you want to make sure your device is compatible, a partial list of ARMv7 devices is here.