A 30 is pretty much the MINIMUM tank size for a pair of larger species SH. SH are hard on water quality, so a sump would be the best way to go. If you go that route, you may want to run it as a refugium to boost your pod population.
I do recommend getting TRUE CB stock from a reputable breeder of hobbyist/breeder. I'd go with Dan (DanU) over at Seahorse Source or Beth (Peka). True CB stock will come to you eating frozen mysis and disease/parasite-free.