Type of Fin for Bing PTLW

Hi Folks,

Just looking for some advice please, I recently purchased a 9'2" Bing PTLW without a fin, i weight 190lbs and and wondering what fin would suit best I have read a lot of positive things about the Greenough 4A but am undecided yet.  

If I were to go for such a fin, what would be the correct size for my weight 9" , 9.5" ?

Your advice would be much appreciated.

Thanks

Hamish 

for the record:

here is a pic of a Bing Pintail Lightweight (PTLW - this one is 9' 6", from Swaylocks archives)

and here is a pic from Bing's website

and this is a picture of the Greenough 4A fin

 

http://www.bingsurf.com/merch-fins.html