I am in the same exact boat, RFID door lock project for my dorm. This is the Instructables for it: http://www.instructables.com/id/Arduino-RFID-Door-Lock/
I have all the parts gathered, ordered the cheap stuff already, measured everything and found the perfect compatible adjustable electric strike after hours of searching: http://www.amazon.com/gp/product/B0095TGQBO/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=AK5EA8E3B8D7
Then I realized the electric strike only works if there's a space in the doorframe for the strike to move through. I can't saw a hole in the doorframe because this is a dorm and I'll get charged to repair that if I can't undo it when I move out.
Crap. One stupid lack of opening in the doorframe and now I can't do this.