Would like to build a decent platform around this upper http://palmettostatearmory.com/index.php/catalog/product/view/id/21781

Mainly just looking for something accurate out to 300 and possible 3-gun. What other PSA parts would you pair with it? I also have a chance to buy a cheap Anderson lower at work, will it fit this setup? Any other suggestions would be greatly appreciated, I'm new to the AR world