They are usually quite quiet.  Well, unless you plug them into an amp with some 12 inch speakers or something, obviously. Much quieter than an average acoustic violin in any case.

But just like using it with headphones? (You can also use it without the headphones if the room is quiet enough, but usually they sound better with at least headphones)  Not likely to bother anyone else.  I doubt you'll actually need the mute at all, unless maybe you want to practice with one for when you play on acoustic or something. 

None of those is going to make much noise, unless you run them through an amp and speaker.  Really it boils down to what shape you like. 

I would recommend at least considering going with a shape that is close to that of an acoustic violin in the places where things like the shoulder and chin rest attach, though.  If you don't, then your options when shopping for a comfortable shoulder rest and etc may be very limited.

An unplugged electric is not all that loud.  Mine is at most maybe as loud as a person talking in a reasonable voice, like maybe if they were talking to someone on the phone.  Which is much quieter than an acoustic violin.

Really you want to look more at what you want than worrying about which electric violin body shape will be most quiet.  All of those will be pretty quiet if you are using the headphones.  But a couple things I suggest looking for is one where the shape of the bottom end of the instrument is similar to an acoustic, so you can use standard shoulder rests.. and it would probably be good to pick one where it has a bit of body up where the neck meets the body on an acoustic violin so you can use it to help find the higher positions in the same way an acoustic violinist/fiddler does.