I would like to get a Time Capsule but have no need for a router as my ISP router works great. I like to keep as much Apple as I can as my current USB external drive disappears after a few days and I have to reboot for the iMac to find it again. I am hoping the Time Capsule doesn't disappear. Is there an Apple wireless external HD that does not have the router function? I certainly couldn't fine one. If not, is there a good third party option?