Taurus 65, 66 and 669 in 357

[BattleRifleG3]

It's looking like I'll be buying or ordering a Taurus 357 revolver in the next few days. I've gotten good price quotes on new ones, and seen used specimens at one shop.

There's a 6 shot stainless 6" barrel (used) with adjustable sights, not sure if it's the 669 or 66 or other, but those are the specs. Might be a discontinued model, but I'm not sure. Condition is fastastic on the metal, wood grips are ok, and shaped to my tastes (they have a flat bottom.) Price is $300. This shop tends to price not too high, but not too low either, with the occasional gouge or super good buy.

There's a stainless model 669 6" barrel on gunsamerica for $225.

A dealer quoted me $355 on new 7 shot adjustable sights stainless Taurus 66, $325 for blued. Same guy quoted $325 stainless and $295 blued for a fixed sights 6 shot model 65.

Question is how are all these models related (quality, interchangeability, etc) and what sounds like a better buy? Hogue advertises the same grip for all of the above models.

[Calvin]

The 6-shot stainless w/ adjustable sights is a 66.
As far as a comparison of the three you mentioned, the obvious similarities are frame size, grip configuration, and the barrels are the same from one to the next. Meaning, if you needed to order a replacement (for some unknown Godly reason), there's plenty of them around. Also, the actions are the same, too. They use the same springs, triggers, hammers, cranes, ejector rods, etc..
As far as the quality goes, how many manufacturers put a unlimited lifetime warranty on the life of the firearm, and not as long as the original owner has it?

[BattleRifleG3]

I thought the Taurus 66 was 6 shot too, but apparently they're all 7 shot and the 65 is 6 shot. 65 is fixed sites, 66 is adjustable and costs more.