BMW X5 3.0i (E53) 2001-2006 Performance Parts - Dinan Cars
Here's another option. Dinan is always pricey but I have never has an issue with any of it and the performance numbers were always a little better than their estimates.
Almost every vehicle benefits by getting more air in and more air out. You should get more out of the software if you have a cold air box and low restriction exhaust.