I agree. I remember a similar post made back in 2011, yet still no individual parts availability nor pricing.
I saw a for sale post recently with a new MWS bolt. I believe the asking price was $260.
I don't think the OP is looking for another MWS upper. I think he is trying to build a lightweight upper for his current MWS lower. If he's looking for another MWS upper, I have a spare one for sale.
Plenty of people run suppressors without switchblocks/adjustable gas systems. It's just nice to have the flexibility of the adjustable gas system.
Honestly, I've owned several Noveske and LMT MRP rifles and I don't think you can go wrong with either.
I don't think it is a necessity to change out the factory trigger, though one of mine now has a Gieselle SSA and the other has the LMT 2-stage trigger from my MWS. Again, it is simply preference and intended usage.
I have two LMT CQB MRPs - one .223/22LR and one 9mm. Between the two rifles I have 8 barrels for them. I love the flexibility of the platform. If you are not going to utilize the barrel change feature then I think there are a lot of alternatives that are just as good for slightly less money...