Surfing Waves

Hey guys, first post, but long time lurker lol... I learned how to surf earlier this summer and can catch waves very easily on a 7'2 minimal that my uncle had lying around, but am starting to feel that it is getting sluggish for my style(charging and very powerful). I used to bodyboard and boogie board so I already knew how to catch waves, and I skate and snowboard so balance is already there. I am looking into getting a shortboard so I can go faster and start doing some cutties and airs.

My uncle has hook-ups at our local shop and the owner has left over Webber Afterburners from last year. The one I'm looking at is 6'4 x 19 7/8 x 2 7/16. I weigh 185.5, but am looking to shed about 10-15 pounds to lose the flab lol and I am 5'8. Is this board good for me or should I go for the 6'6 which is 6'6 x 19 7/16 x 2 1/2. I'm thinking that the 6'4 should be good for me because of the width of the board, pretty much 20 inches. I think that would be good to learn on, but the weight is throwing me. Which do you guys think I should go for??? BTW they are a steal, the guy is gonna give me my choice for 320!! Any advice would be very much appreciated.

Either should work. Both will be a huge change from the 7-2, of course. But if you're going to go for it, I'm not sure the extra 2 inches will make all that much difference at that size range (in adding/subtracting difficulty for you).

yeah I realize that it will be a huge difference from a minimal, but I know that if I want to progress I have to get on a shortboard. I have developed a love for surfing and want to take it further, maybe as a career. I know how difficult that is, but i can dream can't I lol I have a feeling that the extra width on the 6'4 outweighs the extra 2 inches in length in terms of progressing more quickly. The extra float I think will help. Just my 2 cents though.