I was in Dahab Nov/Dec 2007, the job market in that town is over-loaded with instructors, hopefully you can speak a second language other than English, as this is what the shops are needing, the first thing you will be asked is "what languages can you speak". I hope you enjoy just DMing & not teaching much, except for DSD. I do not know if your IANTD instuctor rating will give you a head up, hopefully yes.
My best advice is to pay to dive and learn the dive sites before walking into a dive centers looking for work... the second question you will be asked is "Do you know all the dive sites??
Check out the dive store across from the old Sphinx hotel and possibly buy the dive site guide book, interesting read, especially why the deeper water in Dahab is warmer than the shallower water in Eilat... or why the dive site Golden Blocks is so named, ect. I liked eating the the Cafe 2 doors to the left, the local guys in there are cool, never got sick ect.
You can find long term accommodation by going to Mirage Village hotel
Mirage Village via the seawalk past lighthouse then find Bedouina
::Welcome to Bedouina::Bedounia Real Estate :Bedounia Travel ahab,South Sinai,Egypt on the street just behind the property. Also, talking to locals in the dive shops, they always know someone with a house to rent... small house/apartment will be @$350.00USD per month.
I understand languages are a big deal in the Madives, more important than your PADI rating. Two of my Colleagues worked there a few years ago, between them they spoke 6 different languages.