First, yes, as a C&R it can be shipped directly to your home IF you are C&R FFL (03) holder, and your state law permits it.
Second, there is no real difference in quality insofar as a hex receiver (NOT barrel) vs. a round receiver is concerned. After about 1930 or so, manufacture under Stalin was simplified and the hex receivers were done away with. While I wouldn't consider any of them "junk" per se. you have to remember that the wartime guns were subject to many stressful factors and, to be honest. can appear downright crude insofar as quality of machining is concerned.
As a rule, the older a gun is, the more questionable the metallurgy. Hex receivers are from older guns and quite a few capture pieces were used to rebuild guns for the Finnish Army. I personally have never had any problems from either type of receiver and I have not heard of anyone else, either. The main attraction of hex receivers for some is the fact that many were made before 1899 and therefore don't require any kind of license to ship.
$69.00 is a very tempting price for a starter gun and there are plenty of them available out there since they were produced by the millions. Bear in mind that the $69.00 guns are all Russian refurbs, so they are going to be reblued and most likely the stocks refinished with some really crappy varnish.
Nothing was done about rebarreling them, so the ideal situation is to try to go to a local store that sells them (Big 5, etc.) and find one that has a decent bore.
When selecting, just use your common sense and select the rifle with the best bore possible and examine the wood for cracks and splits. Regarding serial numbers, most, if not all of the refurbs were "force matched" during rebuild, i.e. a bolt that headspaced properly was renumbered to match the barrel (the receivers were generally not serial numbered), as well as other components on the rifle. (I have to make a minor amendment about serials: BATF requires that each gun have a "unique" serial number on the receiver, so any number you see on a Russian Mosin receiver is going to one that the importer put on.)
Regarding the Finn guns, yes, they are generally considered the best of the bunch, especially insofar as accuracy is concerned. They are expensive, but if you like precision shooting, they are the best bet.
There are some American made Mosin Nagants, but you don't encounter them often any more. New England Westinghouse made thousands as did Remington Arms for the Czarist govt. Most were not delivered because of the 1917 Bolshevik revolution and were sold to the U.S. govt. to be used as training rifles, although some were issued to American troops involved in the invasion of Russia after WW I.
So..... When you embark on your search, don't worry too much about hex vs. round or the date of manufacture. Select for bore condition and wood condition.
Also, and this is just a personal preference of mine, the short carbines, i.e. the 1938 and 1944 models have a deafening muzzle blast, so I really don't enjoy shooting them as much as the old 1891 or 91/30 long rifles.