I need a proxy that would enable me to use cli curl/wget with another ip address.
How do I find a paid proxy server that supports curl/wget?
You don't need a special wget proxy to use with wget. An ordinary web proxy will work, like http_proxy="hostname:port" wget some.web.site
As for where to find a proxy, if you want one that'll last longer than 5 minutes, don't use a "free" one. These 'free' proxies are frequently zombie computers and will vanish the next time someone does cleanup, and aren't the sort of junk you want to deal with or be associated with. You can rent legit proxy service, ask your ISP if they have a proxy, ask people in your circle of tech friends if they've set up proxies you can use, or set up one of your own on some other connection.