Julidochromis marlieri pairing?

[elbereth]

I bought four Marlier's Julie juveniles in hopes of getting a mating pair. (Yes, I know the chances are slim but that's all I could get.) At what size do they start pairing off? And are there are any distinctive behaviours that a mating pair will exhibit? Besides the obvious ones like hanging out together and chasing off others?
I'm very new to the hobby so any advice would be greatly appreciated. Many thanks!

 

[elbereth]

I was able to get 2 more today. I'll be moving them to a planted 48 gallon (36"x18"x18") within the next few weeks. I could only keep one pair in a tank that size correct? And what would be some good tankmates?

 

[elbereth]

Bumpity bump.