stoked60 not a problem at all. Board length on the vanguards is not something to go by it will just be a slight adjustment to length that you over come in 2 waves. Giving your wind strengths the 5'4 this will give you that little bit of extra glide on the lighter days and give the option to surf it with out a doubt in my mind. 5'2 will work as well for you too giving you the bonus to sink the tail a little more. Planning on the 5'2 compared to the 5'11 is day and night. Once the board is out of the water and on a plan off you go- The planning Hulls on all the VG are amazing and will blow your mind first time you jump on one.
The construction on the kite side matches any kite brand out there. The FW boards how ever do not loose that magic feel retaining the nice flex characteristics .
Bottom line is you could go for either board and be happy I think. I personally ride the 5'2. The board really allows me to sink the tail a lot more riding unhooked.
I got a price from my local supplier here in Oz, $975.00AU. Thats for board only - I thought they going to be cheaper without the inserts. Also told they won't be available here until March so will miss our 2014 season completely.
I was in Vero Beach during the holidays and had no problems with my 5'0" Vanguard in lighter winds. Other guys were either walking the beach or struggling to stay upwind but the Vanguard was golden in the light stuff. I'm around 165lbs and the 5'0" is my daily ride. I've done the 5'6" (way to much board for my weight), the 5'2" and now the 5'0" and could probably go a tad smaller in high wind. Doubt you will have any issue on the 5'2" at your size, at least for kiting. Surfing may be a little different depending on your paddling ability. Regarding strength, the Vanguard is coming in FireWire's FST construction which has a proven track record for being solid. It's what they used on all their kiteboards last year but the latest build is much lighter.