If you do go with Mega squirt, don't skimp on the wiring. I bought my car with a Mega squirt installed and hated the thing! I thought that it was a piece of rubbish (Tune seemed to change, run rough one day, crap the next. Lean one day, rich the next). Although I was a bit unfair on the system as it was wired poorly with no screening on the input wires. So, make sure you wire it well and take some care with the installation.
You have to keep in mind that the computer is built to a budget. Things like wiring is connected via a parallel printer connection or only being able to run high impedance injectors (unless you use inline resistors) etc. So just keep in mind that you are buying a budget computer, so you can't expect it to be the be all and end all.