Need help picking 2nd fish for 12g

[TriniReefer]

Ok so i need some help picking another fish for my 12g,i think my firefish is needing a friend now.He's been in there since the begining of last summer.What fish should i get?

 

[Bmgrocks]

keep it small
youre prob best off with a Goby of some sort

or just 1 false perc....

i'd suggest u stay away from the pseudochromis/dottyback species, they get very territorrial in Small Tanks like a 12