You’ll need some tools, but they will cost less than shipping and a barrel install will.
This, pretty much. I have all the tools including the spendy internal locking lug backup tool and receiver face lap. I'd be happy to put it together for you but even a non-serialized group of parts and doing it for free sort of qualifies as "in the business of" in the ATF's eyes.
All you really need is an armorer's wrench and the counter-torque wrench. The upper receiver block that's supposed to keep the receiver from collapsing is always too small to be any help IME. The lapping tool put in backwards works well, but the counter-torque tool eliminates all the issues. Torquing to a spec is internet fun time, just give it a honk and try to make the next flat for the gas tube hole. 35-70 ft/lbs is about the range, best if you stay on the low end. You'll need an armorer's wrench to REMOVE the GI barrel nut, and whatever wrench is required to install the new nut/fore-end you put back on. I'd buy all new stuff and not take of the front sight gas block to re-use the barrel nut if it were me, but if you want to keep it GI you can drift the tapered pins left to right and heat/beat the old FSGB off to re-use the nut and delta ring/spring assembly.
I'd get an aftermarket full-float handguard from a GOOD maker like Midwest Industries. It will come with barrel nut/shims and hardware. Then you need a low-profile gas block of the correct diameter to fit the barrel you choose. Get a NEW gas tube and don't forget the roll pin. If you need a front sight that is the height of the carry-handle aperture, such are made that clamp to the handguard's 1913 rail, otherwise if you have a flat-top receiver you can run and optic (I HIGHLY recommend the $99 Weaver one-piece scope mount).
Premium AR barrels often come with a bolt that's headspaced to the barrel individually. I'd look for one of those if you want the best accuracy and guaranteed no problems with headspace. I've never had a headspacing problem with any of my AR builds where I just put random parts together, but you may not be so lucky.