I made a cardboard mock up of what I think I want for the "Cats" .
I made them to use full sheets of aluminum 4x10cut in half 4x5.
I'm going to sit in the cats.
There will be two 7 foot wide in all
the deck will be chain link a nice clear air stream to the prop.

sorry About the Font???
Got them welded. and riveted the rakes on the front.
Starting to put tubing around the edges for strength .
http://i1221.photobucket.com/albums/dd474/d4570/101_2045_zps7limngkt.jpg

http://i1221.photobucket.com/albums/dd474/d4570/101_2042_zpsrc27ld2s.jpg
http://i1221.photobucket.com/albums/dd474/d4570/101_2043_zpskk5wmoni.jpg
I'll deck the whole thing with expanded Aluminum
http://i1221.photobucket.com/albums/dd474/d4570/101_2040_zpsmjxohv16.jpg
Power plant no change yet

http://i1221.photobucket.com/albums/dd474/d4570/101_2044_zps2k25sm3m.jpg

Looks good !! I assume you'll need a bilge pump for each cat...Are you cutting a slit in the gunwale tubing and slipping it over the sheeting ???

Yes and yes.
and a drain for each.
I will cover the cats with camo waterproof canvas
Kinda like kayak

A few thoughts on what you're doing...And these are just that, thinking out loud and not trying to make you head in a different direction than you plan to...
You are going to run frozen ground correct ?? Keep in mind there's going to be alot of stress on those cats as you hinge the hulls in and out of transitional areas from water to frozen terrain... So you'll still need some good structural support considering the added stress of how you'll be using them...Yes, the expanded decking will add support but not for the confined stress you'll get running the cats over something from front to back basically having the total weight in one area..
The rakes are good you have the front covered for the initial entry but what if there's a splash area from the sides...In other words not knowing just how far those cats will submerge as you stand it on it's nose bearing all the weight and downforce plunging into the water...You may need a solid sheet up front for a few feet off the bow to keep the water from swirling over the top...

Lastely, and this is getting "over the top" with the thinking...Being in frozen/wet combination conditions my thoughts even went as far as something like a water tank heater element to keep the water from freezing around the bilge pump when you need them the most...

Now you see how my simple build turned into what it is today...:lol:

Thanks.
I have a few concerns Too.
I'm Planning More support in the cats. The Deck will need some also.
Not sure What or where yet.

I'm always trying to think out side the box, hull in this case.

I'm wondering out loud here But.
What about some small never flat hand cart wheels Up front with some kind of screw jack Lowering thing powered by a 12 volt drill ?
two in back together on a caster set up, up and down on a leaver and cam???
Or maybe a Lawnmower type drive for the front ones run off the winch ???
For emergency 4 wheel thing to help across a long dry stretch of river gravel.
I'm thinking about putting the boat on the trailer backward. Motor/ prop up first toward the truck. Ramps and winch on the trailer , so all the weight is not on the back of the trailer.
I plan on Painting gaiter glide and running Nylon strips down the cats , What about a sheet of 22 gauge sheet metal to protect the cats from sharp rocks and ice?