When i spoke with them they said if i were willing to up my monthly line rental they could sort me out an upgrade price...... If this is something you would be willing to do then you should be able to do it.
I think the only chips you can get are the ones on the front of your bumper
Seriously though i dont think it can be done for cheap. That is taking what you say as a ecu reflash or a piggy back
PM Sent.
Update:
I am currently in the process of getting 3 units up and running for 3 forum members. Any interest please PM me. Once i have successfully built and installed the 3 i will get a full write up and pics of the install.