Pu-239 is no longer being developed. But, you're free to do with it whatever you like.
XBT is good. I have not tested others, there are quite a few. I can say that xbt can handle 180k peers much better than php announce on the same hardware.
For https and XBT, you can use nginx to connect and then forward to XBT, I think they call it reverse proxy. It keeps the communication, site and your users more secure than allowing open http connections.