I think that tank dimensions have considerable impact on fish choice - this is obviously not your TMC 60 x 45 tank (I loved the scapes you did in that tank! & hope it's still around
)
50l tank possibility
45 x 31 x 36 (height) cm
tim gave some examples of the micro "rasboras" - most of these fish will do better in shoals of 15-20 fish & won't overstock your tank given their slim profiles - they'll be more confident & visibly active & less prone to startle (jump) when kept in the larger group
I've recently gotten some
M nanus (they look like the lower pictured fish, so not much color except for the black "flag" ... I'm a bit sceptical about the top photo identification)
Another favorite
M kubotai
- both of these are active swimmers that quickly become confident
I suspect most of the above fish are more "secure" in heavily planted tanks, though a tank done up with roots & leaf & dim lighting would also likely work.
Note the differences in habitat information in the fish profiles
Many of these fish seem to still be predominantly wild caught so traffic past the tank is another consideration
I feel that intermittent activity is more likely to cause jump (flight) reflex than fish that become accustomed to general activity around the tank ... of course, if you suddenly switch on lights in a dark room etc, most fish will display a startle reflex
(I try to keep some "night" lights on around the fish tanks so no
night walkers feel the need to turn on lights )
If you want to track down something less common (I'd check with
Colin Dunlop of the Fish Hut for anything "Labyrinth" )
"Burmese chocolate gourami"
parasphaerichthys ocellatus
I'm keen on "Choco's" of any sort as I find their behaviour/swimming style intriguing, I've not kept this species (lack of availability)
The smaller size of
T espei &
T hengeli might suit better than
T heteromorpha