I chose 2 1/2 b/c in a 1 g, they don't have enough room to turn around if they grow up to full size. Might as well "splurge" and spend an extra few bucks for a 2 1/2 so when they grow, they aren't in too small of a container. Also, it's more forgiving than a 1 or a 1/2 pint etc. A ten g would be the best, but if you don't have space 2 1/2 - 5 g is great.
(acrylic b/c less chance of breaking and don't think they make a glass one that small, I wish they did though)
(acrylic b/c less chance of breaking and don't think they make a glass one that small, I wish they did though)