to reiterate what others have the said, the flyer is not s step-up or good wave board. 6ft is pretty much it's top end as far as size goes. the overall template is too wide for the size of the board & esp. the tail...you start getting into DOH range, you want a more pulled-in tail. i prefer round pins.
the merrick fins are plenty big for someone your size, as well. tho i'm a bit bigger than you & i really like the pc-7 fin (pc-5 for a quad). the k-3 fin will be too small for you. it's a great template, but i couldn't get enough drive out of it when i tried it last summer (& it's supposed to be the driver of the 2 kelly templates).
you want to stay away from the tuflite type boards completely, IMO. they're pool toys, really. if you want extra durability, either get your boards glassed heavier than standard pu boards are, or go w/ eps...both will be more expensive, but your boards will last longer. i'd stay away from the webber's too. i have a real problem w/ boards being made over seas by people who don't surf & most webber's are made by global surf industries, which is out of thailand.
honestly, if you're surfing DOH days, a 6'4" flyer is too much board for you, even for a small wave board. you could easily drop down to a 6'2" flyer if you wanted to stick w/ that outline. i have a 6'2" flyer-ish template that works really well for me in that waist-shoulder or head high range.
just my opinion. good luck in your search.