One of the problems when you get in the 8 weight and higher category is that your selection of medium fast rods narrows down. Some people will choose the fast rods and will overline to slow them down.
Here is a rod that surprised the heck out of me. The Temple Fork Bob Clouser
rod may be a good choice. It has a medium fast action that may suit your stroke. I casted it with a standard weighted WF8F and a head heavy WF8F (more like a WF8.5F) both well. When I was casting with a big puffy indicator (used to represent a wind resistant fly), I preferred the heavier line. For versatility, you may want to go with the Redfish line instead. The Clouser rod is slightly shorter (at 8'9") which may not make a length difference on a kayak. But it should make a "Jack of All Trades" rod for what you want to accomplish.
Another surprise to me was the Redington Predator
. Its shorter length (7'10") makes it a good kayak or panga rod for backcountry fish. It is a faster rod, so you may want to slow it down with a heavier line. I would recommend a 9 weight Redfish line or SA Sharkskin Magnum. If you really want to slow it down, string it up with a WF8F Rio Outbound Short (it actually is a 10 weight line). Either line would help you throw all the different types of flies. I believe that Cliff has the 6 weight version.
My favorite two 8 weights are the Scott S4S and the Sage Xi3. They are fast rods, so you would have to slow them down with a 9 weight line. I would recommend the Redfish taper as a versatile line. It also throws 300-350 grain shooting heads beautifully (I don't think that you use shooting heads in your neck of the woods). The rods have the umph to help you throw out a Crazy Charlie at 80 feet accurately, but they also have the backbones to turn a pissy Baby Tarpon. These are standard 9 foot rods, so they may not be the most user friendly on a kayak. Between the two, the Sage had a slightly lighter feel.
Just a thought. You may want to have two rods for the kayak, so you can be rigged differently for different fishing situations.