Welcome to saltwater aquaria!
I also do freshwater and have dabbled in those shrimp, like the
Neocaridina sp. I currenly have a handful of Amano shrimp (
Caridina multidentata) in a 15 gallon community tank.
You're not going to find the range of colors and patterns that you see in the freshwater shrimps, but in my opinion, the marine shrimp are WAY COOLER!
I mean, what are some of the marine shrimp that you're familiar with? Just of the top of my head, and I know others will suggest more:
Sexy shrimp (
Thor amboinensis) - tiny little guys, but live in anemones (not required) and shake their little backsides like they are on the dance floor lol!
Pistol shrimp, various genera - cool little guys who can close their one big claw so fast that you can hear an audible "pop" - like a pistol - from outside the tank. And, some genera of these pistol or snapping shrimp form a symbiotic relationship with some genera of Goby fish. The mostly blind shrimp will spend all day building and maintaining a borrow that both the fish and shrimp live in. The Goby fish will sit and watch for danger, and at the first sign of trouble the fish whips its tail, which alerts the shrimp, and both the fish and shrimp will dart back into their borrow. I mean, that's way cool to have in your tank!
Fire Cleaner Shrimp (
Lysmata debelius) - Way cool! Large, vibrant red and white. This is one of my favorite, mine goes crazy when I feed the tank.
Peppermint Shrimp (
Lysmata wurdemanni) - Another cleaner shrimp, but also useful for controlling aptasia anemones, which can be a problem in reef tanks.
Coral Banded Shrimp (
Stenopus hispidus) - Just look at this guy! You don't see a shrimp like that in freshwater:
Harlequin Shrimp (
Hymenocera picta) - Maybe the coolest looking shrimp of all! These guys have a very specific diet, and are not necessarily for beginner reefers, but you cannot beat how this shrimp looks:
Honestly, I think my wife and I both like the shrimps, crabs and "critters" more than the fish and corals lol!
Good luck with whatever you decide!