My suggestion is two-fold. First, since you've been gone the exciting 25th Anniversary Mods have been released and out in the field they are wowing owners. They are the real deal, they transform the amps giving them most of the properties that a preamp might. So I recommend either sending your amp in for the mods (any of the cap choices are great with the mods, so it would be cheaper to just mod with the same caps you have especially as they are so well-seasoned). You will feel as if you have a new amp, and it will keep you satisfied a long time.

Secondly I would suggest thinking of the ZP3 phono preamp. It's a great preamp--I'm unfamiliar with your phono preamp but odds are it will be a great match for the UFO amp in either un-modded or modded form. I think especially with UFO and ZP3 with the mods you won't think you need another preamp.

One further note: I have the SE84UFO3 Monoblocks with the 25th Anniversay mods and they work great with my not as efficient as your speakers HR-1s, and have ended my own amp envy or "wander lust." You could consider those, but if your speakers are really happy with your UFOs I think modding the UFO with the 25th mods would certainly be less expensive and would really give your listening a boost. . . .

Best of luck and welcome back.