[HeadlessNorseman]

Just from reading the way you are talking about it, I dont think you realize what goes into boosting an NA engine(or much about turbos in general?). Even at low boost, you need something to control the fuel or it will run super lean, if its an MAF engine you might overdraw the maf to make any kind of power and have to work around that or if its a MAP based system you have to deal with the ECU seeing boost in the manifold and freaking out. You might have to run something like megasquirt or at the very least a piggy back maf controller. If the car wasnt designed for boost you have a lot of work to do and crap to figure out. And your highway mpg wont suffer much, boost raises the volumetric efficiency of an engine which can actually help you gain some mileage in some cases. Its a good idea but it sounds like you have a lottttt of research to do. and home brew na-turbo cars can be very reliable if you take your time and dont take short cuts.