Hello there.
Well I'm a normal size 43 and I wear 5mm socks, and I got the 44-45 size, and It's a snug fit. Personally I allways order 1-2 sizes bigger, and use 5mm socks.
So I guess beeing size 44 with 3mm socks the 44-45 would be a nice fit beeing a little tight at first.
By the way I can say comming from carbon fins the Gara 3000 does not have the same push, but considering price it's very nice. I wouldn't have much problem going to 25-30m, but beyond that carbon is just more energy saving.
By the way I found this information on the C4 blades:
"No stranger to world records, C4 fins have earned divers worldwide more spearfishing championships and freediving world records than any other carbon fin. Complete with a 2 year unlimited warranty. C4 fins continue to dominate the spearfishing industry with the supirior technology, design, and comfort professionals have come to expect.
C4 Falcon 30 - tapered medium stiffeness blade for all around spearfishing, surface swimming and deep diving.
rated to 30 meters/100ft.
C4 Falcon 40 - Stiffer, tapered thickness blade for strong divers and deep spearfishing.
rated to 40 meters/120ft
C4 Falcon 80 - 4 inch longer, medium stiffness tapered blade for the pursuit of deep freediving.
Fin of choice for record attempts"
Well I don't know about you guys but the words "Record attempts" & "Deep" just automaticly opens my wallet and money comes flying out