G'day EL-Phat! You have come to the right place my friend.

Always great to have another EL XR8 on the boards (specifically an EL2!)
I would not worry about getting bigger rims for the time being mate, but instead I'd spend the cash on suspension and intake mods. If you are happy with the stock suspension then I'd say go all out on intake mods and a Unichip.
I'm looking at modifying my intake bits as well, so I have been pricing stuff recently. I'd recommend :
* 24lb injectors + 70mm MAF kit from SVO ~$1000
* 65mm throttle body ~$520
* GT40 upper intake manifold ~$1150
* 1.7 roller rocker ~$620
* EGR spacer ~$100
* Unichip ~$1000
Alternatively, if you didn't want to go the GT40 upper manifold, you could get your current one (the Explorer type one, which flows pretty well anyway!) ported. I am considering this, as over $1000 for a slightly better flowing upper intake (GT40) is a bit steep IMO.
If you do decide to go ahead with the above mods, you will need to modify the ECU to adjust for the new injection and MAF. The most effective way to do this is with a Unichip, which essentially re-maps your computer to operate effectively with the new gear. The good thing with the Unichip is that it is programmed specifically for your machine, and done on a dyno while the car is running. And having this tuning power at hand, you can expect a nice gain in power along with it.
If you wanted to modify your suspension, I can only recommend King springs and Koni shocks, which is what I have put on mine. It has made a world of difference to the handling of the beast, is so much better now!
Anyhow, I've probably bored you and everyone with all this ranting, so I'll have a rest now

If anyone out there can better the prices above, PLEASE let me know!! They are taken straight from SVO (Southside) Ford in Brisbane.
Cheers
Mike