RE: Evo for bump n' jump
I have the K87 in my quiver and its s super nice board and I don't hesitate to call it a real wave board (practically the same rocker as the Acids actually). I?m somthing like 15lbs myself and can comfortable use it with a 6.3 (and probably bigger with some coaxing). I haven't used it with smaller than 4.5, but I gather its possible to use ot with a 4.0 too, so it could be an option. On the other hand I think these kinds of boards sail rather big for their size and epsecially handle big sails and light wind very well. Since you (peterk) is also explicitly willing to sacrifice light wind performance, the K79 seems like the logical choice and I still regard it as big enough (especially dynamically, ie when you are moving).
As for the Starsurfer, I've used both that board and the Aero (07) which is the exact same shape. The Starsurfer is a super nice beginners board but the extra weight compared to the Aero does detract a bit from especially the light wind fun. So, as others pointed out, there will be a bit of a gap in your quiver when youhave no ideal board, since you don't emphasize perfect performance in these conditions I don't see this as a "catastrophic" thing. GEMs argument (regarding K87) is valid to to and will give you less of a gap at the expense of comfort in the high wind range. I don't think the time on water and early planing with a 5.7 will differ much at your weight when comparing K79 and 87 though. The better technique you have, the less the difference will be. The 87 will mainly give you more options if you want to use the board with even bigger sails.