Vehicle ECU / ECM Reprogramming with J2534 and Arduino?

Hello, I have seen some Arduino based OBD2 scanners, and data-loggers, but what I am wondering is:

How can I build a ECU Reflash / Remap / programmer? and what parts of the Arduino system is required, with using a J2534 cross over OBD cable?

Lets say I already have the Manufacturer specific algorithym for accessing the ECU HEX. I have all these ECU hexs saved for various ECU's (for a certain vehicle manufacturer) and all manufacturer logging PID's.

Using this information how would I build an Arduino based system (preferably with a Touch-screen) that will save these ECU ROM's on a internal SD card / internal memory, and Flash / Remap the ECU? and include data-logging with internal SD card saving.

basically I want to create a simple hand-held OBD2 programmer, that you can select options via touchscreen, and re-flash the ECU with pre-configured ROMs for that ECU?

have you gotten any info on this? I'm interested as well, have you heard of a device called "avidcode"