My buddy used a Jackson Fun on our trip last year and he was very happy.  Most of the Grand is flatwater so I would suggest a boat that is comfy in the flats and easy to paddle.  The rapids are not as big as the stories about them.  They are super fun and a creek or river runner would be ideal in dealing with a few of them but out of 250 miles there are maybe five big rapids.  Most of the crazy eddylines I saw where in weird places during flat stretches and not in the rapids.

You will be fine in a well outfitted play boat.

Great feedback, thanks. Interesting about the Fun. I have one and I have been hearing this boat mentioned several times now in different places. Comfort vs play is a big concern. Our party will probably require a few of us to be in the kayaks quite a bit of the time just due to raft space. I did the Green last year in the Fun and I was miserable a lot of the time. The river was low, slow and HOT. So again any comments on the Sniper since I already own it or should I look for a bit bigger play boat?

Tell your group to man up and rent some rubber!  Hell you need more rubber on the trip, I loan you my raft..... it comes pre-packaged with a rower!   When you think about all the crap (literally 336 userdays worth) you take on a trip, the weight and space of a kayak is nothing if you agree to row anytime your kayak is strapped on.

While the grand is the trip of a life time and you want to have fun/be comfortable.... don't buy a kayak that you won't enjoy when the trip is over.

never paddled a sniper so I can't comment

It's not the rubber but the rowers. This is my second time down. The first time I rowed  the whole thing and it was the first river I ever rowed. (You all are absolutely right, if you can read water and are somewhat aware of where you are, this is not a hard river. Even though I had never rowed I had no probs) Three of us had to combine permits to get next year's permit. I have a family of five and I'm the only one who could row of my family. We are asking a friend to come and help with the rowing so I can paddle. With having to combine permits and everyone wanting to invite family we may well end up being short on experienced rowers.
It is so hard to get a permit now that people end up having to combine permits which really cut down on having the ideal group make up. As it turns out to have an experienced oars person on our raft, at least 3 of my family will also need to be on that boat. The other permit holders are forced to decide on family or oars people as well. It gets to be a mess.
Since I can't decide for the other permit holders whether they will trade a friend or family member for a oars person, I decided that my family's raft should be pretty self sufficient and unfortunately full.
In the ideal world I would have my own permit for 16 people and could invite a balanced group of family, friends and experienced rowers. (Not that they are mutually exclusive but you get my point .)

Get tips Kyle, I imagine horn the ditch is a lot different at 800cfs.  The thing that practically drove me crazy with my group was they were so slow setting up and breaking camp.  If you are going down with people who are new to multiday trips, I would recommend planning days of a simple menu and camp to correspond to the days you want to do longer hikes so you have the time to do them. 

Also I was so happy I brought my poogies.  They really were a life saver in protecting my hands from the sun, when I was kayaking.

Suerte,
km