Just a not I am under 21, and my insurance is really not that outrageous. It is actually comparable to that of a honda civic coupe, or something similar (maybe a bit more). Except my car looks a lot better. Thanks, USAA.
You could probably do a lot of those mods yourself if you wanted to, like painting the rims, and installing the GPS. You can do just about anything on the Boxster yourself. Painting the rims and painting the calipers is a day with your car up on jacks and little elbow grease. The rims the picture you posted are painted stock rims. You could either pay a premium for the Porsche Nav aswell, or retrofit one in. And for the bumper I would wait it out until you get a few little nicks and scratched on the bumper before you go upgrading.
Also, what year dash do you hate, the '97-'04 (986) or the '05-on (987)? Your pictures are of the 986, which it seems is easier to work on yourself.
Hope this Helps!