Kenji sells his ecus with atmel non reprogramable 256k chips because they are cheaper chips & 99% of his clients dont touch their ecu profile.

I have a couple of blank reprogramable Atmel at29c256 I could program for you.

I do not recommend uberdata,
I would personally run crome....

Let me know if you need one programmed & if so for what application etc...

The best method would be to put the vehicle on a dyno w/ a wideband & tune it... but meanwhile I can provide you with a general program for your application....