Some tips:
* Scribe the cylinder # on each injector as you take them out. Depending on how they flow after being cleaned you may or may not want to install them back in the same hole but you'll know what you've got. (Usually you'll want the 2 highest flowing injectors on #'s 5 & 6, the 2 lowest flowing on #'s 1 & 2, and the others on 3 & 4)
* Order a new intake gasket
* Take pics as you disassemble it just in case you forget how it goes back together.
* Someone mentioned the screens but I think they remove them anyway when you send them off to be cleaned. New screens & o-rings should be part of the deal and you can just have them not put them in if thats what you want to do. Personally, I've never had an issue with them.