We use three types of hides. Some of our snakes and all three others just have two. We just watched to see what ones they used the most and left them in the tub. Two of the links are from PetSmart but we get our hides when we go to shows or at a store called Animal Jungle.
Hides
http://www.reptilebasics.com/Hide-Boxes-p-1-c-282.html
Exo Terra Hiding Cave
http://www.petsmart.com/product/inde...ductId=2752566
ZooMed Repti Shelter™ 3-in-1 Caves
http://www.petsmart.com/product/inde...ductId=2752588
The majority of the time they use the balck box hides or the Exo Terra Hiding Cave. They usually use the ZooMed Repti Shelter when they shed or after they eat. Changing his hide shouldn't stress him out too much, but I'd leave him alone for a few days after the switch to let him get use to them.
Good luck!