I have tacking elk with .270 Win., .300 Win. Mag., and .35 Whelen, all one shot kills. I have a .338 Win. Mag. that I have not ben able to hunt with at this time but I think it will be a grate rifle, it has a very good reputation. I am all so thinking of building a 358STA, it has all ways fascinated me and I'm shore it would do a fine job.
Personally I think any cartridge from .270 and up with a good bullet will work perfect as long as you can shot it well and have good shot placement. I know others that have used smaller calibers with good success, they take their time and don't take risky shots and it works. I just prefer larger calibers.
As rifles go I have used synthetic, laminated, and wood, blued steel and stainless steel. Brands, Savage, Ruger, Montana Rifle Co., and Winchester. Like them all. Wood, blue steel is my favorite.