Kode and Evo are not the same. Evo are much more slashy, wavy and turny than Kode. The Kode 103 is more freewave-oriented whereas the Atom is more freeride-oriented.
To wave ride : Evo > Kode >> Atom
To freeride & blast : Atom > Kode >> Evo
The Atom is more or less a thinned-down version of the Kode 113 with slimmed rail and much less volume. The Atom 99 will be a semi-sinker for your 85 kg weight (http://www.star-board.com/SpringSumm...board_atom.php
). However, this low volume could provide you a lively and fun freeride board to ride under your feet in heavy chop and wind waves, even with a large 8.x sail. If you can waterstart in light wind with ease, go for it. If one day the wind is too light to waterstart, swap the Atom for the big iSonic 145 and continue riding with the same 8.x sail.
Bear in mind that the 2011 Atom has a power box whereas the 2010 Atom has a Tuttle box, so if you want to use the Atom in waves, it will be easier to find small wave/crossover fins in power box format althought Select do provide wave & crossover fins in Tuttle box as well (http://www.select-hydrofoils.com/en/...ies/bump-jump/
). Do not go any longer than a 40-42 cm freeride fin with a large 8.x sail. The stock 36 cm freeride fin would be a perfect match with your 7.5 Natural sail already.
I agree the Atom can carry a large sail up to 8.0-8.5 m2 with your weight. On our french forum, there is a 75 kg rider who is using his Atom with an 8.5 m2 sail and he's having great fun as of 12-14 knots (http://www.star-board.com/forum/showthread.php?t=13386
Tiesda has been using a 9.5 sail + 42 cm freeride fin on the Atom but he's a light weight rider at 60-65 kg ! (http://www.star-board.com/forum/showthread.php?t=11170