This is interesting. I am considering a similar situation.
Basically, I'd like to print from my phone via bluetooth to a printer. Here's what I've done and where I'm at:
Just bought a new Android (Google) phone. I ditched the Windows phone (nothing like having you home computer AND cell phone crash daily
). Since it's a Google phone, it's very easy to use anything else Google. So I am converting my old Excel files to Google Docs. I hope to have a receipt template in GD that I can customize right from my phone. If I get a bluetooth compatible printer and plug it into the truck's inverter, technically I should be able to print receipts on site.
I have yet to look into the printer thing yet but I will be doing a lot of doc conversion after Xmas. I have browsed the Google Docs templates available and looks like much of the hard work is already done for me.
We'll see :whistling