options for that tank... Hystrix.. retic.. Red retic... marbles (mini specific) for life _
DIDYSIS
breeds mantillas that purportedly stay fairly small (probably hystrix and marble blood in there that helps with that)... a male of most any of the blacks will work for life in a 3foot tank (feel free to blast me but it is true)- as far as getting rays... if your LFS does not specialize in rays dont buy from them.
DIDYSIS
vamptrev
spotfin
C
CODISCUS
all are reputable breeders that are active on the forum with various species... and I actually think
D
Discus Origins
has wild minis as we speak and is a vendor here.