When it comes to Del-ton vs PSA, remember that most of the parts are going to be similar in quality, notwithstanding normal variations. The upper receivers, stock, lower parts kit, buffer spring, etc. All these parts are basically going to be equivalent. These days Del-ton is using a 158 Carpenter bolt and chrome lined carrier, just like PSA.
The real difference is, quite frankly, the barrel. The PSA premium line offers a chrome lined FN made barrel. The PSA CHF is a FN made CHF barrel. Both barrels are excellent for a high round count rifle that is combined with a low powered optic and used primarily inside 300 yards. The simple truth is you won't see a difference in real world performance no matter how much money you spend if that's what you do with your rifle. You could spend big money on a Noveske, Larue or KAC and not see a difference without shooting from a rest. Most ( but not all) Del-tons come with an unlined CMV barrel, which has a shorter life span even if few wear it out. But for essentially the same price the PSA is the all around better choice.
Unless you already have your lower, or you want the experience of piecing the gun together, I'd recommend buying a fully assembled lower, barreled upper, BCG and charging handle separately. You'll have more furniture options for the lower, more barrel choices for the upper, and you can get a quality 7075 charging handle for only a few bucks more.
I've done a couple recent orders from PSA and they seem to ship in 10-15 days unless you order a barreled upper. Then it is more like 15 actual business days.