I am at 4500 and have 2 boats, a 200/409hp and a Malibu LXI/343hp.
The 200 works perfectly with a 422 (12.5x15.5), it came with the 654 (12.5x15), the 422 lowered about 200 rpm's, I am now around 3900 at 34mph.
The Malibu 343 came with a 13x11.5, 34mph @ 3600, it is a lot harder to ski on it than on the 200. I tried a 13x10.5 in order to drive the engine RPM's to a greater torque range but it became even harder to ski, got back to the 13x11.5.
I think you will have a hard time to ski at 36 with your 200/343 at 6800, even with the 1598 (13x14) but if the propeller is available, why not try it?
It is expensive to raise the hp's on an aspirated engine but it is possible, but as someone said here before, "Love, money and horsepower, the more the better"