Agree with Shadowman here. There is no significant difference in driveability (i.e. safety) with stock power versus the pulley/tune, so having the car with an expert like Shelby to get it done, versus waiting until later seems like the right thing to do. I'd also go with the trans cooler (Cooltech or FoMoCo), the engine Halon system and intake stiffener seem to be on the must-have items as well. I have them all and have never considered them excessive or unneeded.
The photos show a beautiful car (of course, having the identical model, I'm revealing a personal bias) and not a day will pass that you won't sneak a peek in to your garage for that satisfying smile. Best of luck with the new ride.
And re the learning curve, the tips that others offer are spot on but, in general, you will forever have to maintain a steady level of respect for the power and performance capabilities of the car. In lieu of any safety nannies, you are fully in charge, and must show a level of situational awareness that today's computers often do for you.
Since your car is still at Shelby's - if I may suggest, I'd seriously consider the pulley and tune. You'll want it soon enough (everyone does), and may not have someone good near by to do it. That, transaxle cooler (cooltech's), and short shifter are must have on most folk's list. Not sure what tires you are considering - the Bridgestone's are pretty awesome.
