Hey tim13, yeah you won't be able to do iPod control.with your base unfortunately. Your swap shouldn't be too pricey because you don't have sync equipped. Crutchfield sells the dash adaptor for 200 when you buy a deck with it, so the price is good actually.
Also, for the time it takes to remove the door panels. I would just swap the front speakers while your doing audio upgrades at the time. Takes like 20 min to remove the door panels if its your first time. Just get a decent set of 6x8s that take 35-50/60watts rms each, should cost you 60-100 bucks to replace the fronts. They will really shine with a quality headunit.
If you have some time to wait, I will be installing my gear probably next weekend. I was going to post a thread on the whole install process. I've never done anything related to car audio installs, so it should be fun! I found it just about impossible to find much information on 2011+ mustang installs.
2011 Kona Blue MT82 V6 Mustang Pony Package 3:31 Gear Ratio, Interior Upgrade Pkg, Security & Shaker500/Sync
Mods (in order of installed): AM Bama SCT SF3 Tuner w/ 87 Hybrid Tune, Airaid CAI, Hurst Billet Plus 2 Short Throw Shifter, Lethal O/R H Pipe w/ Stock Exhaust, Blacked-Out Tints on Rear Windows, Full Ceramic Tint on Front Windows, Metra Touchscreen Dash Adaptor, Single DIN Head Unit, 6.5'' Component Speakers Fronts, Stock Rear Speakers, 10'' Sealed Subwoofer, 4ch. and 1ch Amplifier. LED licence plate lights, LED interior dome lights, FRPP/Dynamic shocks and struts, SR Performance lowering springs, GT500 Strut Mounts, BMR Adjustable Panhard Bar, BMR LCA's, BMR Relocation Brackets. Rear Seat Delete.