Thanx Ian! and Roger!
It is great pleasure to feel the PERSONAL support from you guys and also understand that it will bring benefits for the many other WS like me
I realize that I will need smaller toy when I will grow up as WS and to cover 15+ knots wind conditions
Today I would consider something between GO155/170 and Phantom (depending on availability/price) in order to catch most of the days (usually 2-4 Bft)
(probably Phantom will be more expensive, difficult to get and sell off after :S
May be GO170 will be OK for mine 77kg with its more volume to cruise, starts plane earlier than GO155 and still OK up to 15 knots