looking for a Diamondhead USA VRS-T rail/handguard in 308/AR10

I agree that a budget is required to answer this question as well as familiarity of AR tools/assembly. Your budget will supersede anything comments and possibly pigeonhole you into one option. Also plan on buying a second AR or upgrading the parts in the distant future...no one who follows r/gundeals just buys one gun and calls it a day, regardless of initial budget amount. So only spend within your budget now, and once you have your bearing on what you want, spend the money to upgrade or replace.

Keep in mind that the lower or firearm is an FFL item that is transferred for a fee, whereas the upper is not. You might want to confirm with your FFL if there is any different charges on the transfer depending whether it is a stripped lower, completed lower (ie with trigger, buffer tube and internal parts already installed), or a complete firearm. I recall in some states a higher tax/FFL transfer fee is charged to receive a full rifle compared to a lower. If the upper and lower are shipped separate, there may be multiple shipping charges, so you may want to work that into your budget as well.

Lastly, ammo is more important than fancy toys on your gun and stockpiling ammo should come before any upgrades. A case of 5.56/.223 ammo runs $400-$500 so plan on that next.