I can't say much about the 35 Remington other than it is a rifle cartridge that you intend to use in a pistol length barrel. Not knocking it, just another thing to consider. I of course have several Contender pistol barrels that are chambered in rifle cartridges that perform just fine, but the slower velocities can be an issue occaisionally. The bottle neck case is a little bit harder to load, not a big deal. Of course, factory ammo is readily available. I can't say anything about the accuracy since I've never had one, but I'm sure it's great.
The 357 Max, however, is originally a handgun cartridge, and there are plenty of projectiles that will work at handgun velocities. Also the bullets for the Max are inexpensive and there are a TON of different ones to pick from. The 357 Max is a very good choice in handgun length barrels, and of course is very easy to handload with a good set of carbide dies (no case lube need for resizing). The 357 Max is capable of 150 - 200 yard shots at deer sized game, which is about as far as most of us feel comfortable shooting.
You're right about the chambers in factory TC barrels - it's not that they're bad, it's just that they're not ideal. TC cut the chambers with that goofy conical area just ahead of the chamber that makes the pressure levels match those specified by SAAMI. Of course that is unnecesarry in a closed breach firearm like the Contender. The way that TC cuts the chambers causes a slight loss in potential velocity and accuracy. Not terrible, just not as good as it could be. I have a 14" 357 Max that shoots 3" or so groups at 100 yards, which is not awful, but that's about the best it will do. Still perfectly capable of taking deer sized game, and as I said, very easy to handload for. You can just about forget about buying factory ammo for the Max!
By having a 357 Magnum rechambered to 357 Max, you eliminate most of that funky chamber. You need to note that TC did this, as far as I know, in all their "handgun caliber" chambers. This includes the 44 Magnum, 45 Colt, 357 Mag, and 357 Max. You'll also see occaisionally folks having their 44 Mag's punched out to 445 Supermag for the same reason. If you have a barrel reamed out to 357 Max, or have a custom barrel built, the velocity and accuracy of the Max is outstanding and makes a superior cartridge for the Contender.