I had one of those 31j Vostok watches for awhile. They're alright. They are rugged and keep running, but aren't that accurate. Also, they're fairly large watches. I think most of them come in around 42mm or 43mm. You will need to replace the band on one, too. They're allegedly leather, but they must have used a very stretchy and weird feeling part of the cow.
If you want to spend a little more for a nicer watch, take a look here:
Home of WestCoasTime
I've bought from them and have had excellent service. Though their watches aren't a "name" brand, they're well made. They have heavy stainless cases - I've taken mine in the ocean and used it as a beater. No problems and it still looks and runs great. Also, most of their watches have a ETA 2824 inside. Some snobs look down on the ETA as "generic," but it's an accurate and reliable automatic movement. Best of all, there are so many 2824s, you will never have a problem with it being serviced or getting a replacement part. For the price, there's nothing better on the market. So if you put one of those in a nice stainless case with a sapphire crystal, well, who cares if it's a recognizable brand? That's a good watch at an affordable price, which is what you get here.
If you'd like to spend a little more for a brand, the least expensive "classic" aviator is probably the Fortis Flieger:
I owned one of these for a few years and loved it. Would still have it, but a friend went wild over it and he has it now. I replaced it with a Fortis Cosmonaut and, more recently, picked up a Sinn 656. Both of those might interest you, too.