the multimedia aspect of phones really is something you'll get bored of.... i went and got a camera phone with internet and stuff from verizon, the limited aspects of memory and hte tedious task of entering URLs and saving them takes up alot of time.... you'll get bored of having the internet... the only good thing is that you can get weather and news reports on it, but verizons default news things suck... reading news just sucks on phones...
if you get a phone that has the ablity to use a data cable, to transfer photos for free, get the camera... butsome camera phones will notallow you to transfer pictures off your phone, without paying a dollar a picture.... soo it defeats the idea of even taking pictures, because a dollar a picture is a horrid deal for the crappy pictures you get... it's more cost effective to buy a real digital camera than to get a camera phone and transfer pictures from it weekly
i have verizon and the service is good, very few signal difficulties, but i'm also in a populated area...
just watchout on your plans, they will try and get as much cash as they can get from you as they can
if i were to make my own phone, i would make it like a minature thing, very tiny, and no extra stuff, just a apower button and a number pad