A lot of bettas will eat shrimpies, so I'd avoid them. I chose snails instead of shrimpies for my 5 gallon betta. I have had a nerite snail for about 7 months with Velvet, and I have had a mystery snail for a few days in there. For shrimps you are pretty much limited to ghost shrimp in small towns, if you have a LPS that is willing to order them for you, you could get some red cherry shrimp. Cherry shrimp are an absolute rip off, and ghosties are usually something silly like 69 cents. Don't keep the 2 shrimps together, as the ghost shrimp will kill your expensive red cherries.
10 Gallon Tank:
~Countless Pond Snails~1 Espe's Rasbora~1 Harlequin Rasbora~
5 and 5.5 Gallon Tanks:
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Many of my scaly friends from my original tank from 2011 have passed, except for two! I am in the process of re-doing my tank. :)