Can i use private http proxy with Firefox browser?

I get it is a security risk but i am just looking for a way to be able to register in websites that block connections from tor network (and many sites do). I am wondering which one of these three will represent a less security risk:

  1. Using the Tor browser but switching temporarily from SOCKS5 proxy to HTTP private proxy in the manually proxy configuration?

  2. Using the Tor browser in ssh tunnel and temporarily change the SOCKS5 proxy settings to the dynamic proxy settings for the ssh tunnel?

  3. Using public web proxy, for example like kproxy.com, inside the Tor browser and this way accessing websites using the public web proxy IP?