but does anyone have an idea about the possibility of a way to connect the ipad to the iphone to use the gps chip (which is only included in the 3G ipad, not the wifi only model)?
Are you familiar with "GPS Serial"? In the ModMyi source, it's supposed "to allow use of external GPS in any AppStore application". If/when the iPad is jailbroken, you can run this on it, and the "external GPS" in this case would be the GPS from your iPhone.