Please help a girl pick her board!

Hi everyone, I'm a newbie here! I need some advice on what board to get. I'm a 5'8", 115lb female. I started on an 8ft longboard. I got bored on that and it's SO hard for me to turn - it's very, very thick though I honestly have no idea how thick.
So this summer I borrowed someone else's board. It's a 7'4" shortboard. So it's still a very big board but I LOVE the manuverability of it and I honestly feel like I can get up so much easier on it. I love everything about that board! Unfortunately I have to give it back. So now I need to decide what to buy. I'm an beginner to intermediate surfer. I can get up easily, I'm working on riding the face of the wave, sometimes I get it sometimes I end up in the whitewater, I can turn (nothing spectacular but I can steer and turn).
My biggest problem surfing is am definetly lacking in the arm strength for paddling to catch the waves (As you can see from my height and weight I'm lanky, LOL!) I can paddle out fine but paddling to catch the waves I cannot do like the guys I see!!
So what should I get?? I asked at a local surfshop and also some friends and they all suggested a fishie board in the 6'6"-6'8" range. I don't know why I'm reluctant to get that after being on a shortboard. Will it steer as easily? Will it be as fun? For me there is just no comparison between my longboard and the shortboard (even if it IS a long shortboard, KWIM?) But I'm at the same time I'm afraid to spend and get a too short shortboard I'll be horrible on.
So what would you recommend? A fishie or a shortboard? What size?
Thanks so much!
So this summer I borrowed someone else's board. It's a 7'4" shortboard. So it's still a very big board but I LOVE the manuverability of it and I honestly feel like I can get up so much easier on it. I love everything about that board! Unfortunately I have to give it back. So now I need to decide what to buy. I'm an beginner to intermediate surfer. I can get up easily, I'm working on riding the face of the wave, sometimes I get it sometimes I end up in the whitewater, I can turn (nothing spectacular but I can steer and turn).
My biggest problem surfing is am definetly lacking in the arm strength for paddling to catch the waves (As you can see from my height and weight I'm lanky, LOL!) I can paddle out fine but paddling to catch the waves I cannot do like the guys I see!!
So what should I get?? I asked at a local surfshop and also some friends and they all suggested a fishie board in the 6'6"-6'8" range. I don't know why I'm reluctant to get that after being on a shortboard. Will it steer as easily? Will it be as fun? For me there is just no comparison between my longboard and the shortboard (even if it IS a long shortboard, KWIM?) But I'm at the same time I'm afraid to spend and get a too short shortboard I'll be horrible on.
So what would you recommend? A fishie or a shortboard? What size?
Thanks so much!