Sizing Potatonator or alternative

Hello Y’all,

This is my first message celebration and a beginning in the forums. 

I am thinking to get a 600 FW Potatonator but have some questions. Actually besides the questions that I’ve got, I cannot find an online affiliate around my region with that board in stock. So I am looking advice for an alternative board or another size (Going to down to 510 would change a lot, 4 lt a bit too much to lose)

I am living close to Black Sea coast, its not an ocean. So I’m surfing mainly mushy waves . In winter, I fly to Mediterranean coast where we get some good waves (like a good day of an ocean) other then that I travel to California, France west coast and pretty frequently to Portugal to surf. 

I have a 7’3’’ minimal which I like very much and a shortboard 6’2’’ (6’2 x 20,25 x 2,5)

I am a beg/intermediate. To be more precise I ride green waves and make small manoeuvres. 

I am 1.76 cm = 5.77ft. and 78.5 kg = 173 lbs. Starting to lose some weight and probably I’ll go down to 73-74 kg in 1 or 2 months (Approx. 160-163 lb), I am 33 years old and fitness a bit above average. 

Would like to have your comments.