Probably the best 2.5" barrel .357 magnum ever made is Colt's
Python; but finding one for sale might be a big problem. And if you do,
expect to pay a premium price for one in LNIB condition.
The 2.5" barrel S&W model 66 or 686 will serve you well at a fraction
of the cost of a Python. The 66 is Smith's K-frame (target sighted)
.357; with the latter being the L-frame with target sights.
OTOH, you would do well to find a Ruger 2.75" barrel Security-Six.
These are often found LNIB, priced in the low to mid $200's. If you
desire something a bit different, try a Ruger SP-101 in .357 magnum.
The come with the standard hammer, or a spurless hammer model
can be had. SP-101's NIB are currently price at $339.88 in my neck
of the woods.
Also, for a around the $400 dollar mark, you can find a NIB Smith
& Wesson model 60 in .357 magnum.
.38's vary in price and quality. Some are not worth the effort
it took to produce them; others are OK, and some are great. I will
only discuss the ones here that I feel are worthy of mention:
a) any Smith J-frame .38 caliber revolver. This includes old
models 36, 37, 38, 40, 42, 49, and 60; as well as the new stuff.
b) Colt's D-frame .38 caliber revolver. The Detective Special, the
Cobra, and the Agent models.
c) any Ruger* DA .38 caliber revolver.
*FootNote: FWIW, all Ruger's are proof tested with loads that run
30% above normal.
Best Wishes,