Preamp suggestions 1200$ used

If your sub has a high pass connection I would use it for a music only system. The high pass connects to the speaker terminals of your power amp, so an extra pre-out for the sub is not needed.

Like Sugarbrie, the obvious contender, especially for a novice, is Rogue. You could buy a used one here and resell it without loss if you did not care for it. Whatever you pick, be prepared a dramatic improvement. Have fun

Go with the Rogue preamp as it will match up well with the Rogue amp you already have. Also pick up a few power cords for the amp and preamp combo!
Happy Listening.

Try the Marsh P2000. You can get it new at your price point. It has all the qualities your list.

geoff,
i drove tyler linbrooks with a rogue 88 (stock) and 99 magnum combo for about a year without the slightest complaint whatsoever, very nice. out of curiosity one fine saturday i wanted to see how the cary sli-80 integrated would perform at home with my tylers and front-end. i was very impressed to say the least. simple, musical and involving, i was thinking music, not hi-fi the entire time, cd after cd after cd...i do not use a sub myself, but the sli-80 does have a sub out which would suit your needs. from what i've read the sli-80 takes another leap forward with some tube swapping, something else to think about.

life and this hobby being what they are, of course i ended up purchasing a cary v12 privately and still use my 99 magnum pre, but if i wanted one less box, the sli-80 integrated would definitley be on my list. i understand this suggestion would make your rogue 88 irrelevant, but i'd say consider this now rather than later,if you are in no rush to buy.
otherwise, you could hardly go wrong picking up a matching rogue preamp. mark at rogue is a stand-up guy and a pleasure to do business with. great amps and great customer support.
great choice in speaker
hope this helps you decide
cheers