I would like a recommendation on a spare parts kit from the AR experts on the site.I want a kit that can be stored in the buttstock and that will be for field/emergency repair.Thanks in advance for you replys.

Many spare parts kits contain parts that are not really "field replaceable".  It is no use carrying around an ejector, spring, and pin, if you don't also plan to carry a punch, hammer, and vise.  Duh.

However, the DPMS BP-01 kit seems to have most of what you will need.

In MY opinion, the field replaceable parts to have are:

Extractor, its pin and spring (assembly)
Firing Pin
Firing Pin Retainer ("cotter pin")
3 Gas Rings -OR- better, a McFarland Ring.
Hammer Spring
Trigger Spring
Hammer/Trigger Pin
Disconnector Spring
Cam Pin

My "emergency field repair kits" are stored in Stow-away II grips right on the rifles, which look similar to the stock grip, but with a trapdoor.  They are available now from Bushmaster ($13?), but I have not seen them anywhere else.  They used to be made by Lone Star Ordnance, which is now seemingly out of business.

Some people just prefer to keep a complete bolt assembly.

The GI cleaning kit is a necessity!  All you need is there (which should include Break-Free and patches, if not, add them).

Other parts you might consider for back at the shop are a complete lower receiver parts kit.

Bushmaster makes an excellent field repair kit with most everything you need.  This is something that would be better in a range bag or pack however.

However for a buttstock kit for 'immediate' use there are only a few things you should think about:

1) Spare Bolt - much easeir to swap to a new bolt should your ejector or extractor have an issue, or the rings crack (fix old bolt later when there is time with the parts in the field kit in your pack).

2) Spare firing pin - USGI type, not a Ti one.

3) Spare Cam Pin

4) two or three spare firing pin retaining pins (easy to lose one of the buggers in the dark).

5) two fire control pins (same pin is used for the hammer & the trigger).  Very important part, while they rarely break - if one does your SOL.  These are very small & don't take up much room.

All these parts could fit inside a trapdoor pistol grip (like the lone star) or inside your buttstock with a basic cleaning kit.