Your first Steadicam vest is a milestone, and you should enjoy the experience. Some manufacturers advertise a great vest, but you need to know what you’re looking for, and this will help.
Before getting a pro vest (SC Merlin) you will want to go with a generic, cost effective one like the Glidecam gold vest.
Glidecam gold vest does well for the price and supports up to 38 lbs.
Some vests are sold as part of a kit, arm/vest/sled, which will greatly benefit a novice.
If you're a pro buy the PRO model (SC) and use the Glidecam as a back up.