You can get 1000 connections for a 4g/5g mobile proxy that supports udp with openvpn from a few places but i highly doubt you will get true unlimited connections setup from many places. Many max at 15GB a day, you said per GB so I don't know if that means you need a lot of data or a little. In theory the more connections the slower your speeds will get on dedicated proxies. Not sure if that's important or what you are doing.
Otherwise check marketplace to trial a few and see if it matches your needs.