Revolvers that are ideal for carry use and range use are not often the same revolvers. Ideal range revolvers will often make great bed-side/home defense revolvers, or woods carry revolvers--but the factors that make tham good for the range (adequate weight to comfortably shoot a powerful cartridge like the .357 magnum; long enough barrel for good velocity and precise sighting) make them uncomfortable or at least potentially inconvenient to carry (assuming you mean concealed, with a permit).
If you try to split the difference, you will probably end up looking at something like a 3 or 4 inch mid-size steel-framed revolver, and the most common and suitable examples are the ones you mention--the GP100 and the S&W's, say the 619 or 620. Shopping used, you would be able to look at a S&W 65 or 66 (those are stainless; their blued counterparts are the 13 and 19), which lean a little more toward the carry end of the spectrum by being a tad smaller/lighter.
A little farther toward the carry end of the scale, you could get a 3" S&W model 60--a steel version of the 'j-frame' 5-shot you've already experienced, in .357--or a Ruger SP101--another 5-shot steel .357 'snub', but a little heavier and stouter than the S&W.
Best course of action would be to get out to where you can shoot (at a rental range) or at least handle (at a gunshop) examples of these various revolvers to see how they feel--and how you imagine carrying them.
As for expense: the Rugers will probably cost a little less than the S&W's, and are fine guns if that difference is critical. Used should be cheaper than new, and you can get a good idea of the market value of different models by extended study at an auction site like gunbroker.com.
