Super heavy lift rocket(450tons) that can be spawned in the scenario edtior?

[palebluevoice]

I've fallen in love with the "Energy Project" addon; my favorite rocket by far, and I use it for launching most of my spacecraft and payloads, but the problem is, it isn't strong enough. I want something to be able to launch a fully loaded XR5(450 tons like in the title), and that I can spawn in the scenario editor, like the energia?; does anyone know of a good one? If not, that's okay; I'll try to work out the Quasar's config file, just if anyone has a good recommendation, I would appreciate it!