There are 2 main choices in your revolvers....Ruger Vaguero's and 1873 Colt clones or originals if you are so lucky.
Barrel length...5 1/2 is one of the most popular due to it's balance in either style.
If possible try to live fire each and see what YOUR hand prefers.
Have shot SASS for over 20 years and see many entry level shooters make decisions that don't always work.
Most SASS shooters will bend over backwards in offering you their gear to try first then buy.
Many times the existing shooters know of someone selling gear....firearms, clothing etc. sometimes there are tables of stuff offered for sale after the match.....go ask the shooters for their opinion and you will get an earfull!!
Randy
AKA "Bugler"
PS. Try .38 spl's in your rifle with a round nose or roundnose flat point bullet. Some Uberti's are finicky and will only feed the .357 casing using the same type of RN of RNFP bullet with a moderate to wimpy load.
Lastly, log onto the SASS Wire and read the boards that will answer much of what you may be wondering about.
Have Fun!!!!