? about new rims

I've got a '98 Sport 4X4 With the uglu 3 spoke 16" stock crome rims. I would like to replace them with new 16" rims but have questions.

1. What bolt pattern do I need?
2. What is the max back spacing?
3. Who has a good selection of rims to fit
that I can mail order from?

I've surfed around but places like Tire Rack and Performance Products only have crap for rims to fit Explorers.

 

[Alec]

5 on 4.5
Max is 4.5", 3.75" is a good bs for the Explorer
Try 4 Wheel Parts.