Trimac - just so you can trade me some fry :lol: . Seriously, if you're going to devote a 125 to just 2 fish, I'd go for the Trimacs. Long term, I guess I'd just hope they didn't have a falling out. I guess there are always dividers.
2nd choice Midas. I haven't had any jags before, that is my next adventure after growing out my current batch of Midas.
Yeah 6x2 is nice. Glass cages has a 125g wide that is 72"x24"17" that is going to be my next purchase. Best of both world foot print wise might have to do more water changes when full grown though. Only $330 dollars too.
I have one of each. I like the 125 for two reasons. First it looks much more than 5 gallons bigger than the 120. Second, the fish seem to like it better, the 6 foot footprint seems to give more room for territory.
i think a 6ft would look better but u have a feeling thats not what your asking about
for breeding trimacs *** heard you might have to separate them so the 6fter would be easier to divide and leave the fish more room to swim in (3x18 compared to 2x2). the 6ft length would also allow the fish to get some quick "laps" back and forth compared to a 4fter.
so id say 6fter but it really depends on the type of fish.