Fenn have not announced anything in the way of a Mako6 double. They currently offer the Millennium double and the XT double (the XT is a slightly more stable version, has adjustable single footwell cockpits fore & aft).
When I asked Oscar about a V10 double he said that "there will be a double some time in the future"... so I'm not sure if they've even started the design yet.
Rob
Currently Epic V10 Elite, Epic V10 Double.
Previously: Swordfish S, Evo II, Carbonology Zest, Fenn Swordfish, Epic V10, Fenn Elite, Red7 Surf70 Pro, Epic V10 Sport, Genius Blu, Kayak Centre Zeplin, Fenn Mako6, Custom Kayaks ICON, Brian's Kayaks Molokai, Brian's Kayaks Wedge and several others...