I prefer Concave, feels more like my skate deck, but if you want flat, check out kampus as well as cassette. You would do good w/ a 40 or 41, but I wouldn't go any larger. I'm 5'7" and 160, and feel fine w/ a 41"
I have the Gator Boards Skate 43 and have really liked it. Its a tougher board in my opinion. Ive been riding for a long time now and there have been no cracks, splittings, delaminating and the grip hasn't even started to peel off. Unlike my hyperlite scape (grip peeled off after 1 season) and LF WUD (which dis-assembled after 1 1/2 seasons).