I have the choice between a Bic Vivace 270 96 L. and a Bic Veloce 278 101 L.
Witch is the best buy for sails from 5 to 6.5. I weight 165 pounds (72 Kilos)

Thanks for your help

windmeter,

the Vivace is an older board slightly, with a more dedicted faster shape, and if I remember rightly a bit of a pig to gybe. I used to race on them way back.

The Veloce will be easier so sail and more fun, slightly wider and more manouvreable.
With your weight both would be suitable for the sail sizes you mentioned.