For tuning the stock ECU you can use HPTuners or EFILive. A copy will run you $500-$800. Either will be able to handle what you're looking for and are very user friendly. You can download a demo copy of EFILive for free. HPTuners is similar.
Look at MS if you want: a cabled throttle, boost, custom VVT timing, etc.
I think efi might have some comments on mileage versus a 292 if you ask nicely