Replacing the JBL Synthesis head unit with a basic amp for a Tablet

I'm seriously looking into swapping out the JBL front-end for an Android tablet setup similar to this one. (long video of the same basic idea)

The first component I need to decide on is a replacement amplifier.

I know I could just use the Aux on my existing unit, but I'll need the space that it uses to store the other components like the steering wheel control adapter, FM stereo module, etc.

Amazon.com lists a ton of them, and I know there are lots of other sources for buying like Crutchfield, Best Buy, blah blah blah.

note: I'm more of a computer geek than car audiophile so I'm looking for recommendations on which units would be recommended to best match with the speakers and such that are already in my 2006 Sienna Limited since I'm happy with the sound quality as-is.

Any thoughts?

I've found the TATO adapter, so I'm wondering if the right way to do this is grab that and then just look for a way to get RCA output from the tablet to the TATO. If I go another route I need more information about the JBL unit to make sure I match up with the speakers, sub, etc in the Sienna.

PS. For why ... I'm an Android geek and, if they ever ship, will also be using a Navdy. And I'm going with a tablet over a full double-din Android system both for easier upgrading over time (I tend to keep my vehicles for a very long time) as well as the ability to do the same set up in my campervan (Ford E-350 diesel) and just swap the unit from car to car. That does mean that, instead of mounting the tablet permanently behind a double-din adapter kit I'll be making a setup a bit different than linked at the beginning so that I can pop it out easily.