What? You have bin kiting for 6 years and buy a 3,5? Are you going out in more than 60knots? You will need a lot of wind to have fun on that one and very hard snow - and it´s probably never going to be fun anyway... On hard snow you´ll need less power than on water, but in deep powder or deep vet snow you´ll need more...
I would say leave it at home - when there´s enough wind for that kind of small kite the visibility is going to be very very bad and you´ll have problems seeing you´re kite.
And the same goes for harness - use your normal waist harness - works much better - you´ll get a better balance and a better pressure on the edge. We ONLY use waist harnesses even for courses.
And many of the shops that are specialized on snowkiting chose only to sell waist harnesses... A climbing harness really sucks on the snow - I had to use it for a little while due to an injury, and would discourage it strongly! You´ll have a lot more trouble to jump properly, and loose the free feel of the legs, and again loose some of the ability to put the pressure on the edge that is needed...
So my advice is take your normal gear for water - it will work much better!

Good luck! Knowing how to kite on the water - it´s no problem just go for it and have fun!
