Antenna advice for WI 53098

[Nails]

We are about midway between Milwaukee and Madison, 10 miles north of I 94. We live in town, not in a low area, no towers within 3-4 blocks.

Pre-digital, we received many stations from both Milwaukee and Madison, without a rotor. Our rooftop antenna (2 story house) is about 10-15 years old. We have 1 TV on 2nd floor and 1 on first floor, with a professionally installed amplifier in the basement. Our TVs are analog with converter boxes, DVR is digital. Some Milwaukee channels that were strongest pre-digital, we no longer get. Most channels, either direction, are spotty, some days good, some not. Sometimes a channel will disappear during a program. Since digital, we cannot use both TVs at the same time. I don't know why.

What is TV/antenna/set up suggestion so we can use both TVs and receive both Milwaukee and Madison channels?

Why are some antennas only UHF and not VHF? How will this affect my reception? Do VHF channels actually broadcast on UHF numbers, even though we seem to access them on low numbers?