Good choice! Especially on getting the full length. Classy. I've seen your gun closet and you'll have time for a shorty later.
You can do a lot better than 1300 for a standard. You should be paying that much or less for a loaded and closer to $1100 for a standard. The NM price sounds about right. Springfield ran dry (
![Angry2 [angry2] [angry2]](/xen/styles/default/xenforo/smilies.vb/019.gif)
) on both of the models I wanted for months when I was buying them, so I got them both very lightly used.
I think the loaded is a very good upgrade over the standard for not much $$$. For me, the jump from standard to loaded was definitely worth the $$$, while the jump from loaded to NM wasn't.
The match trigger and front sight are the biggest improvements you'll notice if you fire them side by side. They help the feel of each shot big time. Standard front sight is about the width of a 275m silhouette, while the NM front sight is about the size of a 400m silhouette. It also has a match barrel, match flash suppressor, and .5 MOA windage adjustment (instead of 1 MOA on the standard).
The Match rifle on top of that adds a hood to the rear sight that you can flip to make .5 MOA elevation adjustments (standard and loaded only do 1MOA). It also has a match gas system and spring/guiderod. The hood and the spring/guiderod you can replace on your own very easily if you ever feel like they'll make a difference for you. There are ways to unitize the gas system on your own too that are not as simple as replacing a part, but I haven't gotten good enough to really get into that yet.
I have no info on SS vs regular barrel. I don't like the aesthetics of the SS so I never looked into it much. Match barrels are not chrome lined, so they're not as durable as the standard barrel in field situations. And the "match" accuracy over the standard barrel only lasts ~5000 rounds (probably just about the same time one would get good enough to notice the difference!)
M1As are not the easiest things to scope well. The short answer is to get a mount that is steel (not aluminum) and attaches to three points... both side mount screws and the stripper clip guide. Anything less won't keep zero. Make sure you get a scope with long eye relief too. Most mounts won't allow you to mount the scope further back (I had to get a $$$$$ GDI TA70 mount with an extended rearward rail for my IOR Valdada... It'll be here by the weekend) Try to get a mount that has a channel to see the irons through as a backup... none of the good ones quick-detach. The rifle stock is meant for the very low irons and you'll need a cheek rest to get any weld at all with a scope (even jaw weld doesn't usually work without one). Lots of people are making drill-on kydex
M1A junkies are all about having all GI parts. Early commercial Springfields were put together with GI parts on a commercial receiver. As GI parts started drying up, Springfield started making their own cast ones which aren't always as good. I never really got into this too much. I suppose I would if my rifles stopped working, but they run fine and they're probably not 100% GI. A preban gun would get you more GI parts. And I suppose if you ever wanted to put a pistol grip on it you'd need it to be preban too, but it doesn't sound like you want to with this one. (the Socom has a brake instead of a suppressor, so you'd be fine with putting a pistol grip on like Mark did)
The only problems I've had with my rifles have been mag related. Luckily, you missed the days when GI mags were $50 a pop. CMI just started making USGI ones again by the assload and most of the country is getting brand new ones from them for less than $25. The market for preban ones is $20-$25 now. At these prices, don't bother with $15 Taiwanese ("Just like USGI!" my ass) or any other ones that are not USGI. They just don't feed 100%. Zero of Ten of mine worked right when I got them. I replaced all the springs with +10% Wolff springs and now maybe 7 of 10 work. Besides, they're pitted and blued instead of parkerized like USGI ones. I'd trade all 10 of them for 4 USGI ones now (I've since gotten a bunch of USGIs and the T57s just sit around). Feh.
Come to an appleseed and you can get some hands-on time on mine. I have a loaded and a scout.