Speaker for 11x12 room

@OP, the best placement is what you propose - speakers firing down the room towards the wall where you propose to have the piano. You will still benefit from a curtain on the glass door. You will get some reflections off the piano so it it can go in another room, it would be better. Also, it will allow you to get your chair away from the wall.  And ideally, some acoustic treatment behind you listening seat would be beneficial.

There's a wide variety of speakers that will work in that space so you are not necessarily restricted to standmounts - though you do want a speaker that has good control in the bass and that will work relatively close to the wall. That said, the Harbeths and Kef LS 50s are good suggestions that will definitely work well in the room.

I would take a serious look at those Used Fyne Audio speakers that were suggested, they work well with tubes.  Firing down the long end at the 8.65 foot wall. At least the first several 6.5 feet on each side of the speakers is symmetrical so you will get a consistent soundstage. If the piano is going to sit behind you you will be forced to be nearfield to your speakers to listen and some room reactions can be ignored. Good luck!

@daviddas Thank you for the intro to Philharmonic Audio!!  Added to the list ...

@fthompson251  ... concur, the Fyne's are worth every penny!!

Some good info OP!!

1st I would move piano to bedroom. Then I would start with putting speakers along the 12.1 ft wall.  Left speaker spaced 3' from the glass door wall with curtain. The right speaker having about 6ft space between it and left speaker. Position the back of speakers at a distance different than that of the distance from side walls. If possible place a low profile equipment rack along the wall shared with bathroom, not at point of 1st reflection, treat that wall with sound panel at 1st reflection point.  Place listening chair about 6ft from front plane of speakers.Treat the wall behind chair with absorption panel.  Make adjustments from there.

You have received many good recommendation for speakers.  I will only state that I use Fritz carbon 7s in a similar sized room. Sold direct with 60 day trial period. Very tube friendly. 

On room placement I concur with Mesch…use the long wall. The piano maybe can stay, however. On speakers, the BMR Monitors seem ideal, but Totem Floorstanders like Forests are also. Revel FS226Be are another.