I prefer 1/35 for armor, the kit selection is enormous; tanks, artillery, motars, machine guns, you name it, it's most likely out there. Go to any model hobby website and browse the inventory of most everything you want. The kits for men and equipment supplement the armor and vehicle kits.
Academy, AFV, Dragon, Italeri ( figures are no good ! ) Tamiya. Just to name a few.E-bay has a ton of kits out there that are old releases and re-releases. 1/35 kits are easy to see, as you get older your eyes can't keep up with the small details, at least in 1/35th scale you can see things, I know because I also build 1/48th WW 2 aircraft and H-O trains with a highly detailed layout. Eye strain for me exists everyday ! So I lean toward the 1/35th for a break.
These are simply personal views as I recommend them from experience over 30 years when Mongram had several fairly good kits including the Sherman w/ rocket launcher, The German armored car, and several others when 1/32 scale came out, which is about 9% larger than 1/35 of I remember correctly. then Tamiya and Italeri started out with fairly good kits of the day. ESCI and others as well had fair kits.
Figures from DML are by far the best in detail and when combinned with the re-tooled Tamiya figures( finer cutting of the molds) they blend well and make a great diorama. One secret about any diorama, in practice, the smaller dios' with 2-4 figures on it make a good subject. My largest dio is that of a winter scene in the Ardennes with German troops walking ahead of a SDkfz 251 Halftrack, the dio base is only 6"x 14" with a base of styrofoam covered with white glue, water and baking soda for the snow.
Two dio's with similar ideas can be arranged to appear as if the two forces are fighting or suggest a separate operation miles apart. A larger 12" x 12" dio on a simple wood plaque suggests that the Panther tank commander is confering with an infantry officer that is standing pointing in a particular direction, next to the tank is the Schwimwagon used by the infantry officer to do recon. Next to this dio is a much smaller one. This has two German infantryman walking in the mud and snow along side a BMW motorcycle. This arrangement could suggest that the head of the main body of troops is a recon unit and the officer is relaying info from the point group, the BMW. It's all how you present the dio, not the vastness of it.
Keep it small, detail it with equipment, but don't overdo the ground cover, or you will detract from the main point, the men or vehicles. I might suggest that you take a look at the rest of my posts here in the forums as I suggest some simple tricks for enhancing paintjobs, and the like.
Best of luck and you have the help of all the folks on these forums, so hang in there.
johncpo