Hi Matt, good to hear you like the FW, awesome allrounder. The 82/86/92 and 102 all have a relatively similar feel on the water, just obviously the extra volume helps vs body weight. Plus once you have a FreeWave, it's hard to switch to a Grip unless the conditions are a bit more constant/the board is not too much smaller. That's why I would go for the 92 actually, even if it seems a bit too close in size, I think for the good days, which will still be gusty on the UK South Coast, you still need a bit of volume and the jump from FW 95 down to Grip 86 might be a touch too much for your weight. If you asked for an ideal range, I would have probably said Grip 92/FW 105. For a one board solution the FW is of course great, but like anyone, those good days are special and the FW will of course come to it's limits with small sails and good waveriding conditions.
The 86 is of course still an option if you are used to riding boards this size, it's pretty thick and floaty in the centre. But I know from experience that most of our heavier racers, love the 92/102 as their waveboards for good conditions, often combining it with a FW 95 or 105 for the less than perfect days/bit more speed for B&J? hope that helps, perhaps you could get a test ride somewhere?