Best hydroponic system & style for low headroom

Hi all, iv got a 1.2 x 1.2 x 1.8m tent currently growing 4 plants in coco 20l pots hand feeding, i average anything from 16-24 oz, but they always get too big nearly touching the lights, im wanting to try the wilma system but dont know which size to go for as that system takes extra height up aswell, i was thinking the 10 pot system in 6l pots to keep them short sog style but will i yield the same as i am now? Or theres a 8pot system with 11l pots but i fear they may get too tall, which would be the best pot size for yield but limited headroom. Tia

i got 0.35m x 0.35 x 0.77m a lot of LST and a fast flip if you can get clones you can flip to flower faster.

I've became a fan of SIP style growing myself. See the SIP thread on here for some ideas, I've included my build on there (a while back).