Surf & paddle

Hi all,
I need some advice. To keep it relatively short
1) I am quite experience in SUP (no surfing) with a 14' (~4m20) race board. I use it in lakes (we have many), rivers, but also the ocean. I mention this, since it suggests that standing up & stability is not an issue for me.
2) However I am a surf-newbe, more or less. My temptatives to come home surfing ended typically in being smashed by a large hollow wave: to cure that I took some classes in surfing (with a 9' softboard). I loved it. But the crawl-like technique of accelerating produced an inflammation in my shoulder, so I try to change that by joining both activities: the paddle and the surf. That means however, I cannot rent boards: no one has such boards in my region
So I need to buy a board without a bigger test-phase.
And that is, where it gets complicated. Should I go for a longboard type surf-paddle-board ? Or a shortboard-shaped one (they will be 8'5 - 9'2 to paddle with'em) ? I live in Bordeaux, France, if that helps to get more refined advice.
Thanks!
I need some advice. To keep it relatively short
1) I am quite experience in SUP (no surfing) with a 14' (~4m20) race board. I use it in lakes (we have many), rivers, but also the ocean. I mention this, since it suggests that standing up & stability is not an issue for me.
2) However I am a surf-newbe, more or less. My temptatives to come home surfing ended typically in being smashed by a large hollow wave: to cure that I took some classes in surfing (with a 9' softboard). I loved it. But the crawl-like technique of accelerating produced an inflammation in my shoulder, so I try to change that by joining both activities: the paddle and the surf. That means however, I cannot rent boards: no one has such boards in my region

And that is, where it gets complicated. Should I go for a longboard type surf-paddle-board ? Or a shortboard-shaped one (they will be 8'5 - 9'2 to paddle with'em) ? I live in Bordeaux, France, if that helps to get more refined advice.
Thanks!