Dinny,
MGM's barrels are of excellent quality, most folks here would agreee. The 357 Max is (in my opinion) one of the finest cartridges the the Contender has ever been chambered for, so I'm sure it will be excellent in the Encore also.
The lightweight barrel will probably be fine for hunting, but might heat up during reapeated firings, but that shouldn't be any real problem. I suppose you don't intend to use it for extended target matches anyway. I'll be that it will balance very well with the set up you are considering.
I say go for it! You might talk to a tech person at MGM for any real advice though!