I feel that if you stay with the loaches then the sev's are your best choice. I think that they tolerate other fish pretty well, will fill the tank nicely, and will breed reguarly like my green sev's did with my discus and angels. No damage was seen durring any breeding period either.
I also fill that the nics would work to on all accounts just like the sev's.
but if it was my tank i would put sal's or grammods in it with no loaches. their prettier to me and i like overly protective parents.
Just my 2 cents worth.