Any differences in Telescoping Stock Assembly parts?

[Kilryth]

What should I be aware of when shopping for stock assembly parts? I want a milspec tube, and I plan on staking the castle nut. I want a VLTOR EMOD stock, but I want to make sure their stock assembly parts are the best I can get (outside of the stock itself). Parts such as the extension tube, buffer, action spring, castle nut, locking ring, etc. I don't know what brand to get, and I don't know if there's any upgraded aftermarket parts either.

I don't know which buffer size to get. I plan on building a standard-weight 16" barrel upper with a mid-length free-float gas system. Mid-length seems to be the more durable/reliable way to go; correct me if I'm wrong. CAR and H-buffers seem to be the most popular. I will probably get an H-buffer unless something else will fit it better. When would an H2 or H3 be appropriate?

Thanks

[ForTehNguyen]

for a middy CAR or H works fine. I use H buffers in my middys. Some people have run H2s in middys. H3s are mainly for carbines so ignore those. H2/H3 start to get near the borderline of cycling reliability so some play it safe and go with an H.

[spamsammich]

If you like the EMOD, get the full combo kit. It will have a CAR buffer, but that's not the end of the world. I run my middies just fine with a CAR buffer. hell, my 16" LMT works fine with all ammo so far with a CAR buffer. Shoot the gun first with the weakest ammo you're likely to use or the ammo you use most frequently, then decide what buffer weight you need.