Hey, I have an Antec 1200, and the front fans are definitely removable, just... a little tricky to do so. Though, if you're not afraid of a screwdriver and using your hands, you have nothing to worry about. While time consuming, the task doesn't require anything like wiring experience.
Rough step by step guide for front fans:
1. Take side panel off
2. Use screwdriver to unscrew drive cages
3. Disconnect fans from powersupply, fan controller, etc (don't worry about the speed knobs in the front just yet)
4. Pull the cages out
5. There are little tabs on the cages holding the wiring to the side of the cage, pull those tabs open so you can remove the wire.
6. There are screws on the cage holding the front metal grill on, remove these and then pull the grills off. (You will have to deal with your speed control knob at this point, don't worry too much about it, just push from the front and it'll pop right out...some force may be needed)
Remember, that's a rough guide. I may have forgotten some things, but if you built your own computer I'm sure you'll be able to figure out the gaps that I forgot. Just be patient, and know that there IS a way.
Post here again if you encounter any issues or have any other questions.
I would, for the front and rear, just buy another set of TriCool fans like Megaman said. Those won't have the plug-ins to the case mounts you've had before on the back and the little dials on the front, but they'll have a switch you can let dangle somewhere for adjustment just like before (just harder to reach).
Regarding the 200mm.. Do NOT buy a coolermaster 200mm, they DONT FIT!
Buy the replacment made by Antec, avoid any headaches about getting a fan that doesn't work.
Others on the forum may have replaced their 200mm with success in our cases, but I don't know of any and will just recommend the antec one.
Links for fans:
http://www.amazon.com/Antec-Big-Boy-200-Computer/dp/B000V6FKGM/ref=sr_1_1?ie=UTF8&qid=1337187410&sr=8-1
http://www.amazon.com/Antec-TriCool-120mm-Blue-LED/dp/B00066FHEW/ref=sr_1_1?ie=UTF8&qid=1337187402&sr=8-1