Do get the 336A w/o the barrel band. Typically, they will be slightly more accurate than the ones with the barrel band. However, the difference is slight and can be offset by other factors. My Glenfield M30 (A M336 with half-magazine, and birch stock and dovetailed front sight- no barrel band) shoots at or under MOA with it's(mine too!) favorite load with a 170gr bullet. My M336C in .35rem will also do this with it's favorite ammo, so........(has barrel bands..)
This is better than over half of my bolt action rifles, some with extensive gunsmithing to make them more accurate (attempting to get them to shoot MOA). Also note that Marlin chose to make the new .308MX's without the barrel bands..................
BTW; the Glenfield M30 is the 1970's "K-Mart" equivalent to the "Big-5" version you mentioned. The cost cutting is in the stock, and bulk purchase by the distributer/retailer.....Hence, just the "nicks" you mentioned. Just make them let you look over the one you're taking home before you do the paper-work. If the cosmetics aren't up to you're expectations, make them un-box another. It's you're money, after all....!
I don't recall ANY .30/30 ammo that you should initially avoid. Whatever Wally-world has is ususally main-stream ammo, and should work well. Its up to you to find what you prefer....Winchester, Remington, Federal, Hornady, ect. 150,170, 125, 160gr, ect...
Personnaly, I'm not really wild about the LeverEvolution (note the emphasis on the "E", not the R........... Cost doesn't justify the ballistics, since I can approximate the long range ballistics with my hand loads at a fraction of the cost.
The performance of the Hornady isn't significantly better than what I've gotten with my handloads. My prefered load(s) are either the 150 or 170gr Remington Corlokts over either 36.0gr (w/150gr) or 34.0gr (w/170) of Reloader 15. The velocities equal the published factory velocities from a 24"bbl, (mine has 20"bbl !!!).
Just go out and shoot that various ammo to find out what the gun prefers...... Then, take the rest and get out and get some meaningful practice by "plinking" at various targets and variable ranges to get a good feel for the rifle. I do this with in the off season with "other" lever actions I own, (two other Marlins, two other Winny's; Looking to add another- maybe a .308MX , or , a .32-20, or perhaps a .327RugerMag if Marlin throws one our way.... or who knows,,,, maybe that M94 in .410 a local shop has ?????)
Of all the deer my brothers and I have killed over the past 40yrs, "who'd thunk'" that my brother would kill the largest whitetail deer (killed back in Jan. of this year, on the RUN, with a Win. M94, in .30/30. (BTW, he's hunted big-game all over N.America -including AK and Canada- and two other continents......) that either of the three of us have taken. (I'm retired from 25yrs as a gamewarden and I've shot a "few", including some really nice ones. 300+, perhaps ~50 with the .30/30.
Of all the rifles he owns, he chose to do the deer "drives" with his reciever-sighted .30/30........... He got this good with his .30/30 by a LOT of highpower competition with M16's in the Military (20+yrs as Airforce Sec.Police guarding Nuke's) and his National Match M1 Garand. He says there's NO WAY he's going to spend half a day "busting brush" driving deer, toting his M1, when the "Winnie" as he calls it (or Hurty-Gerty !!) weighs 3lbs less,and fits the hands better !!!!!! He claims he shoots about "two- 2lb coffee cans" of 160gr FNGC cast bullets over 10gr of Unique powder over the summer "plinkin" beer cans and empty shotgun shells at 20' to 120yds....... See what I'm talking about !!!?
Your only "Mistake" will be to not get one, and when you do, to try to make a "FrankenMarlin" as you stated...... A sling, and your choice of either a reciever sight- or Scope--- is all you need to do. Then spend your money on either ammo, or reloading tools/components and gas to go to the range to Practice-Practice-Practice.........
The .30/30 has aquired an underserved reputation of a deer wounding cartridge. It also shoots much flatter than its reputed. The problem has been the ammo producers publishing trajectory data with 100yd sight-ins and comparing this to the latest gee-whiz magnum with a 250-300yds sight in.
Sight your .30/30 in for +3-inches at 100yds. You're good to 200yds plus with "point and click"......
Also, if you shoot at a LOT of deer, you'll eventually miss or wound one. Thats why it's called hunting, not "shooting" deer.