I got your PM about the keel weight, I have built quite a few different variations, I think the one that is the most useful is a piece of 2 inch PVC pipe about 2-3 ft long filled with lead beads (scuba diving weight), when just put caps on the ends. I suspended the weight on the both the Oasis and the revo by just attaching 4 lengths of spectra string (that's the grey rudder string used on the rudder system), that string is around 500 lbs test and extremely strong, you can get it from your hobie dealer for I think around $.22 cents a foot, I use the stuff quite a bit so I by 30 ft at a time, and just keep it in the garage (handy stuff). You don't have to do anything special when parking on the beach or anything, it just moves out of the way, who cares if it gets scuffed up a little.
Here is a rendering of one on the bottom of one of my boats (from when I made the idea up):
This one is the one I made for my TI, I also have one made for the Revo, and another for the Oasis.
NOTE: It doesn't need to be pointed, just regular PVC caps work fine.
The TI needs close to 50 lbs
The Oasis needs around 30 lbs
and the Revo needs around 25 lbs of lead
Lead is kind of expensive (around $4.00 per lb), so I stole the lead from my wife's scuba diving weight belt, lets keep that on the down low, since she hasn't noticed it yet).
Here is another one that I use on my Tandem Island that fits into the mirage drive cassette, and is retractable, and also can swing from one side to the other (like a swinging keel). I actually still use this one when I'm out kayak sailing my TI.
Here it is retracted, it clears the ground when on the scupper cart:
Here is me sitting on the edge of the boat, it's impossible to tip over the boat. (however as you can see I'm all wet, this was attempt #2, it does nothing to improve your ability to balance if your un-coordinated like me ( LOL)
Here is one of my old Revo's, I used the PVC pipe type keel weight on that boat, and sold it with the boat, when I sold the revo last year.
Here is a pic of my TI in kayak mode, I use the retractable keel weight in the rear mirage slot, If it gets really shallow I just pull the whole works out and lay it on the deck. Unfortunately because the TI is so large, the keel weight has to be around 50-60 lbs in order to be able to use that large 33 sq ft rigid wing sail in kayak mode.
The nice thing about wing sails is they have hardly any heeling force (the force trying to tip you over)so they are very safe for kayak sailing. I still don't take that out in kayak mode if the winds are over ten mph, just to much sail for a kayak (that wing sail has almost as much sail power as the stock TI 90 sq ft mainsail). That wing sail is 20 ft tall off the water, so you have to furl it and take it down when on rivers with trees (LOL didn't think that one thru)
The weighted keels do slow you down a little (drag), and unfortunately if you sail near weeds or grass, it inevitably gets all caught up in there. I'd go with the side kicks, and turbo fins, and forget about a dagger board if it were me. Just remember the whole works (Hobies complete system) is really all designed to be used while pedaling ( ie... the sail, sailing rudder, sidekicks, etc), they really know their stuff when it comes to designing kayak sailing kayaks (why fight it LOL).
Hope this gives you some ideas. Most people use Hobies inflatable AMA's (sidekicks), they are not very expensive, and from what I hear really work well. If it were me I would try them first.