I would fold.

Like you said, so many flushes kill you on the river.

The tight reg SB, is probably either checking to check raise a set or double FD or to check call with a good flush draw. I doubt he is ever donking the flop and then check folding the turn. The board is definitely good for a check raise if he can get his stack in OTT.

When he check raises us, say the fish folds to make in simple, we are 50/50 with our hand against KKxx with no flush draws. There is no point flatting the turn and folding if he raises so we would be stacking off on a flip, at best.

When he flats, he doesn't put another dollar in unless he makes his hand, so we don't have implied odds against the SB.

Against the loose passive player it's a bit different. He is betting the turn so it's likely and it's likely he will pay us off on good rivers. Could be an argument for flatting if we think there's a high chance the SB doesn't x/r us, but I really think he will.

We can't really bluff raise the turn because it doesn't look like we are going to have any fold equity with a loose passive player betting and the tight reg checking. I do think this is an interesting consideration though comparing doing this with say a double non-nut flush draw.

We don't have any flush blockers we can use to bluff the river, so a river isn't going to be super exciting to play.

Id xc and donk bluff on clubs (assuming we dont have a str8).

Dont mind a fold tho

It is a 20 card wrap, btw.