Thank you all! It has being a lot of help.
Answering... I use all kinds of fins...as I got back in surf one and a half year ago I got myself a 7'0 evolution EPS Thruster. After two months I swapped it for a EPS 5'8 Twin Fin and rode it so far.
Now I changed both for a EPS 5'8 that I use either as tri or quad, and this would be my groveller board and a 5'5 TwinFin (intended for those windy days because here in Rio we get loads of afternoon ESE-ESW winds).
About my issue with bigger boards...as we all know, small boards are less stable, but even though, I find that bigger ones in overall are more of a hurdle than a help. Sure, they improve the wave counting, but if believe they are too forgiving at my mistakes and I can't give myself that luxury: you don't need to make a big effort to paddle in or out, nor step properly on the board neither weight your body accordingly, and these are the main issues with my surfing right now, about all, the thing is: except for their paddling power, on medium to bigger sized waves on beach brakes they make it harder to get out on the lineup and, on wipeouts, they are kinda scary - duck diving it requires lot of energy and so do turtle rolling.
My biggest question is: how small a performance board should be for someone like me?
I misspelled the lts, the ones I'm looking for are
5'8 x 19 1/2 x 2 3/8 29 lts (if I counted it right) EPS Thruster Round Tail (this one's follows the HyptoKrypto shape)
5'9 x 19 1/4 x 2 3/8 27,2 lts PU Thruster Squash Tail (this one has exactly the outline mentioned
https://www.tpattersonsurfboards.com/poolparty)
Both have a midpoint close to the nose.
thanks !