Here's a couple of options for you that would complete your lower!
budsgunshop.com/product_info.php/products_id/144877/alexander+arms+uta65+tactical+complete+upper+6.5+grendel+16+black+cerakote+aluminum+receiver+m-lok+handguard+for+ar-15 />budsgunshop.com/product_info.php/products_id/131686/anderson+b2k612df000p+optic+ready+complete+upper+6.5+grendel+16+black+barrel+7075-t6+aluminum+black+anodized+receiver+a2+hand

William, personally I'd go with a M4E1 from aero precision. Here's a link to one with a 18 inch barrel wich would be the perfect length for hunting if interested...................... budsgunshop.com/product_info.php/products_id/718008924/m4e1+threaded+6.5+grendel+assembled+upper+receiver+w+atlas+r-one ...................... Buds doesn't have a picture or much information so just click on the link and scroll down to where it says model number and upc, just Google the upc to find pictures and information. Unfortunately they don't include the bcg or charging handle. Here's a link to a bolt carrier group/bcg I'd recommend............................ budsgunshop.com/product_info.php/products_id/718006846/fz+6.5+grendel+bcg ....................... then any milspec charging handle would fit. They also make items to help with upper/lower wiggle called a (Accu wedge). It's a little orange piece that puts pressure on the upper taking away any wiggle. Honestly wiggle won't affect accuracy or function but it can be frustrating to pay alot of money and your AR rattles. That's the route I'd go, aero precision makes great products and I have a couple AR builds using their products. Hope this helps.

Hi William and welcome to the Buds Community. The Anderson Upper would be the ticket if a 16 inch barrel would suffice : budsgunshop.com/product_info.php/products_id/131686/anderson+b2k612df000p+optic+ready+complete+upper+6.5+grendel+16+black+barrel+7075-t6+aluminum+black+anodized+receiver+a2+hand - Cheers and stay safe!