I would start checking out building plans for a run, just a basic, 10x6 or so. Sketch it up on paper or "paint" on the computer. Google might have a free design page? Once you have a plan, get on lowes.com or home depot and price lumber, 1/2 inch hardware cloth, and a larger welded wire for the upper portion and roof. Ft Knox isn't too expensive to build, cheaper than a dog run. You'll also need 2 medium/large hinges, a gate latch, and a carabiner (those little clips climbers use that people also put on their key chains) to secure the latch.
After you have a price quote for a secure house for them, then you could wait till Easter for when people get ducks and only keep them for a week or so before they realize what they've gotten themselves into. You'll be doing those ducks a favor! Last Easter I took in 5 of them to find them appropriate homes. They weren't the breed I wanted, but they still needed help. They were plenty tame from being carried around by kids.
Right now I have a black swedish hen that was rescued... she was raised alone in a rabbit hutch, she thought she was a dog. She was so very friendly, until my ducks taught her about being a duck and she became as rude as they are. Only coming around for food. Quackers used to come over for a back rub and would sit in my lap too! She has better things to do now I guess.
Once you have a little Ft Knox for them to live in, you can take your time on finding just the right ducks, and not have to worry about anything happening to them when they're safely penned up.
Most any breed can be friendly, though some like Runner ducks are a little more flighty and nervous. Not all, but it's common for them to be that way. If you wait until Spring, you should be able to find 2 drakes easy enough. The only worry I have is if they're buddies, you'd want them to have been raised together.
