Sounds ace. Problem is, if it's unlocked and jailbroken, afaik that means you've voided your warranty straight out of the gate: good luck getting tech support further down the line.

*grumbles about iPhone arrangements*

... if the OP has to have one or the other of iPhone/G1 I'd be inclined to go with the iPhone for the reasons mentioned - someone I know is a happy (and busy) iPhone user.