Compatability Issues for DPMS .308

[UBFRAGD]

Doesn't Midwayusa list AR10 triggers? Too rich for my blood. I did a little polishing and my trigger (from a DPMS LR kit) is SOOOO nice.

[ar15barrels]

Does it matter which manufacturer of the buffer spring and buffer to use? I am planning on using a DPMS Upper, so should I get the DPMS Buffer and Buffer Spring? Otherwise, could I use a Stag buffer and buffer spring?

The brand really does not matter, but the type does.
There are normal AR-15 buffers and springs and then there are 308 specific buffers and springs.
You won't be able to use an AR-15 buffer and spring in a 308 build.