looking for nice PC trio

Have you looked at Audio Engine?

The Audioengine 2 was reviewed positively:
http://www.stereophile.com/budgetcomponents/1207ae/index.html

I was in the same position and ended up going with a decco65 amp/dac, a pair of silverline minuets, and a klipsch subwoofer which is working very well for playing spotify and streaming XM from a macbook pro.

I also have audio engine bamboo a5+ but my daughter absconded these for her room and they sound pretty damn good. The decco/silverlines have better detail and are more open sounding but needed the help of the subwoofer. The audio engine are workable if you only want background sound and not really critical listening.

what about sub if any?

If you get the A5+ I would set them up and use them and see how the bass performs in your room. If you want some extra heft, go ahead and add a sub to the mix.