I really like my 4" 357 Ruger Police Service Six. It's more compact, lighter, and more streamlined than a GP100. The SP101 is another nice one from Ruger, and a 3" would be a nice compromise for range and CCW. I have a 2-1/4", but only use it for CCW. The SP101 has a 5-shot cylinder.
For 44 Magnum my S&W Model 69 is just about perfect. As an L-Frame it's a little big for CCW, but as a field gun its great. It's the same size as a Ruger GP100 or a 686/586.
As for cartridge versatility I've been playing with a S&W Governor, which chambers 45 Colt, 45 ACP, 45 GAP, 45 Schofield, and 410 shotshells. Some see it as a gimmick, but I think it's a good snake/field carry gun that I also use as a hotel nightstand gun (I travel a lot for work). It's basically a big bore snub nose revolver, but a little too big for CCW except under a heavy coat.