Yeah you could go wireless, if you like the look. Ugly in my book. Smallest I have ever seen is still the size of a half a pack of cigarettes. If you want to do the "vent" procedure, it can still be done with a single contact and 2 magnets. Mount the contact approximately 12' up side of jamb and install one contact for closed window and one for open window. If you really want to jazz it up, do contacted screens. Should have a local guy that can make them up for you for anywhere from $55.00 to $100.00 per screen. Contact me for more details.
Chris