A very smart guy with two FD's said that since my car is an every day driver that I should get the Pettit computer since it is plug and go and don't have to worry about tuning etc. Plus it is pretty inexpensive.
I have the Pettit and it is great. If you get more mods you can get a new chip for $50. I do think the PFC is better but there is nothing wrong with the Pettit. Most people don't tune their PFCs anyway. Once tuned they just sit, just like the Pettit will. You might even be able to find one used.
a pettit computer or a PFC or a PMC have nothing to do with driving your car everyday. All these items do is give you different fuel and timing maps to accomodate modifications to your car which could yield a "leaner" than anticipated situation. (to keep the damn thing from going boom).
driving your car everyday is in itself the best thing you can do for it. Otherwise, all it means is that you'll be changing the oil more often (and other maintenance items more often)
But, you can rest assured you will have less problems than if it sat in the driveway all week long.