Fredrick,
I tie all my musky flies with a tandem hook set-up. Having done a fair amount of muskie fishing with gear over the years - usually "burning bucktails" in MN - I discovered that many if not most of the hits I got from muskies were often nips at the end of the spinner/plug. This was especially true when the fish was following the bait high in the water column....which is often how you'll hook 'em - they'll follow the bait fly with their nose right on it or inches from it, then suddenly seize the back of the lure right at boatside and make an 90 degree turn downward. My bucktail spinners are made with tandem trebles and I almost always got the musky on the rear hook. Based on this experience, I like a beefy hook in the back one third of the fly secured with a solid joint to the forward hook. Long streamer flies with the hook way up front are fine for stripers but I like a stinger for muskies. They're too darn hard to get a strike - you want to make sure you hook him when Mr Musky finally bites you.
Also, consider that you'll be fishing shallow water on Marsh Creek probably in the vicinity of woody debris and emergent vegetation. You'll want your flies to ride hook upward so as to avoid some of these snags. Musky flies are a blast to tie but they take a lot of time and materials and I cringe when I break one off on a snag. Do yourself a favor and tie 'em "clouser" style and weed guards wouldn't hurt. For hooks, I just go to a local tackle store and get a pack of heavy duty plastic worm hooks. These make a good forward hook.
Here's some pics of flies of the type I like for muskies. Don't go too overboard on size. The conventional wisdom among muskie guys is to use smaller baits in springtime - I'd say 5-7" would be what I'd put together. Good luck on your trip - let us know how you made out.