I think some of the new bacteria products can come close to instant cycling (a day or two) - at least that’s how I cycle my qt tanks (with
fritz turbo start or biospira) and I’ve never seen an ammonia reading on the seachem badge.
My dream 13.5 nano would be -
Pygmy geometric perchlet
Pink streaked or possum wrasse
Tailspot blenny
High fin or yasha shrimp goby with randals pistol shrimp
If doing that list I would add the wrasse or shrimp goby first and the blenny and perchlet later. Sometimes blennies nip at coral so you may get unlucky (I did with a pictus blenny).
Other fish to consider include-
Eviota and trimma gobies
Captive bred rainford goby
Azure or springers damsel
Swales or rubre swissguard basslet
Yellow assessor
Cleaner goby
Wheelers shrimp goby or any of the smaller shrimp gobies
I don’t like clowns in nanos- too big and too aggressive but I get the appeal