I'd like to get the D spring, a third magazine, and a shoulder rig. Who should I get these from. I know the spring and mags will be easy for a source. A quality shoulder rig, idk. Im currently emailing black hills leather as for the same price as a galco Miami they will custom make one that's for an m9a1

Also should I be realistic and get just standard mags instead of giving my nut for the dust resistant

I drink the cool aid on the sand resistant mags so I say get one.  Midwest has them at a decent price and Beretta currently has them on sale with free shipping if you buy more than one.

http://www.midwestgunworks.com/page/mgwi/prod/beretta-92-magazines/JM9A115