You'll want to check your axle to crown height and the fork rake to find something close to what you have or you might change the handling in a way that you won't like. First fork that comes to mind is the Surly Long Haul Trucker. Also, check Spicer, they usually have a wide variety of forks that aren't too expensive. QBP's house brand, Dimension, might be an option as well.

I've done touring on my fixed Crosscheck, 3 days or so at a time, and found a rear rack with small panniers was sufficient. You find after your first trip you really figure out how to pare down what you need to keep your load as light as possible. In warm weather you can really go a lot lighter: no tent, sleeping bag liner instead of a true bag, etc.