All a matter of personal preference :biggrin:
4 way free float handguard - I like Samson, but many others avail. - Troy Indust., YHM, etc. I think the better ones replace the delta ring and clamp on the receiver.
Foregrip - I have GG&G, but again, Many available.
Stock - I love the Magpul CTR. Also just got a Vltor Emod and it's pretty good too.
Pistol Grip - Hogue on all mine.
Sights and other add ons - Really a matter of preference.
Have Fun :biggrin: :biggrin: :biggrin: