I'm working on a lightweight build. I purchased an AIM lightweight BCG and plan to run an adjustable gas block. What should I run as far as a buffer and spring? Do I want a lighter buffer with a stiffer spring? I was looking at the tubbs lightweight flat wire spring and taccom ultralight buffer, but I'm open to recommendations. Thanks in advance!

You really don't want a strong buffer spring.  You have a very light reciprocating mass that is around 9 oz.  You'll adjust the gas to get that mass to just lock back on an empty mag and if you have a strong spring you'll slam that light mass back into battery really fast and hard.  I went with a 10% reduced strength spring and with the adjustable gas, I can keep the action cycle speed reasonable and keep that secondary recoil impulse soft (the BCG going back into battery).  This reduces scope shake.

Thank you so much.

Going with the reduced power spring, should I just use a standard weight buffer?

I went with Taccom’s ultra lightweight buffer and the 10% reduced strength spring and my gun operates very well.  You could go with a standard buffer, and tune your gas for it.  I found that the standard 3 oz carbine buffer was not as smooth as Taccom’s setup, even after removing the weights.  You can do your own experimenting.  Adjustable gas allows you to have a wide amount of options.  I went as light as I could, but others have been successful with standard buffers.

FWIW. I have tried tubbs, standard, and reduced springs with taccom, carbine, and h2 buffer on each. I have a sentry adjustable gas block and all of them tuned to the same setting surprisingly. I have a standard bcg. Despite all tuning to same gas block setting. I felt that the tubbs gave the best feel overall.