The only thing to remember about the iPhone is it only really likes talking to macs (I'm neither here nor there on apple, just prefer Galaxy S interface and screen, and it talks to my macbook), a lot of the stuff you want to do will need more than basic file transfer to a computer I think... The solution is to get a mac as well!
I don't fully agree with this statement. I connect my IPhone4 with Windows and ITunes no problem. File transfer etc work like a charm.
I'm even connecting my phone with Linux Ubuntu 10.04 and can do all accept backup IOS!
MAC PC's are very expensive and if you are not using it for graphic design it is not worth it.
Bang for buck a normal desktop PC will outperform a MAC.
To give you a idea. I just build a new work pc for myself. For about R13k I got the following:
Monster motherboard with 6 core AMD processor. 16GB of RAM. 1TB disk space. 2 x 24" LED screens.
Monster video card to drive the 2 screens. Logiteck wireless desktop setup.