Cavalry Arms lost their FFL (long story) and this company bought their machinery. They are the only polymer lower that I would consider using. It is fine for .223 and .22rf, maybe .300BO, but I don't suggest supressed with them. Heavier calibers tend to flex enough to have to make sure the mag and bolt catch are perfectly tuned which might require some parts filing.
They will take mil-spec triggers, but most drop-in triggers won't fit. I suggest NOT using the buffer retainer pin as it can be a potential cracking point, again if the geometry is not perfect.
The stock is the shorter A1 length, but a buttpad can be added. You can buy them direct from GWACS for $195 in several colors, but if an auction is to your liking, the starting price saves you $10.
They were selling for $99 to $130 stripped and $150 complete when Cavalry Arms was in business.