I've been researching intensely for one. I have similar issues, such as I don't want a lot of junk hanging inside because there isn't a lot of room.
Yoyager has proven itself both wired and wireless, but I am not prepared to drop that kind of coin into it. No matter which way you twist it with options, they are going to run $700+
Read the reviews carefully on the lower end systems, I have heard many complaints of the cameras fogging up and they are shot after that, not serviceable.
This one seems to get good reviews, and they are priced inbetween low and Voyager. I haven't pulled the trigger, because I don't necessarily want that big screen on my dash.
RearviewsafetyHappy shopping and I'll be watching this post.