I used to use an ELM327 bluetooth with a jailbroke iphone. It ended up being a pain to get up and running, but I wasn't aware of the ELM327 w/ wifi at the time of purchase.
Now I'm waiting until I get an upgrade from my provider to switch over to an android phone!
As far as I know, transmission temp should be available - it might depend on what software you are using on the iPad. Might want to look at other programs and what they support. I searched quick on google and didn't find much support for OBD fusion. There is a thread on here about getting trans temp to work on Torque, though. Directs you to here:
http://torque-bhp.com/forums/?wpforumac ... c&t=346.00Not sure if this is of any help to you.
As far as digital gauges - my girlfriends Prius has no mechanical gauges. The speedometer is available on dash, but everything else is run through the dash computer. I find it a little hard. At least with our gauges you can get a feeling of what is up with your vehicle at a glance. Though even if the Prius had a similar gauge cluster, I'd still probably have no idea what was up!