If you are going to get an AR built, I would HIGHLY recommend you decide EXACTLY what parts you want and the configuration you want BEFORE having it built to avoid having to change them later, and paying for duplicate parts. Talk it over with him. For example do you want flat top or carry handle? Bull or standard weight barrel? Clamshell handguard or free float tube? Standard trigger or something like the Jard trigger I have in mine? Gas block, front sight, or folding front sight? That way you will wind up with a rifle designed to do exactly what you want and suited to the purpose.