I have read about the raspberry Pi here with much interest.  A few months ago I was asking a IT tech who did attend our church about my wanting to be able to pull the odometer readings from my Freightliner (with C15 CAT engine) and into a tablet with the click of a button.  He suggested a Raspberry Pi.  He was giving his 5 year old son one and envisioned him learning a lot from it.

Does this sound like a viable option?  Suggestions please, as I am new to these devices.  I have some programming experience but not in the needed language.

I did buy a "display GP-E" from CAT which I have not installed yet.  It hooks onto the wires going to the diagnostic plug and will display the odometer readings and such if It works "as advertised".  By that I know that the information is there if I get enough help to be able to capture it and send it to the table.

Is there a better choice of device?  

Where is the best place to buy the Raspberry Pi (or ??) devices.  The guy at Radio Shack had no idea what I was talking about until he looked it up and then would not tell me if other stores in the area stock it. 

TIA