Dear Todd
I do not have p10s but have had p8ltd and will offer what help I can. Calloway and a number of other audiogoners have had the p10s and you might try to contact him.
With regards to room size that is not a huge room but I expect it would be fine, I used p8ltd in a larger room and had no problems filling it with sound. These speakers might be an even better match but come up less often for sale. There is a chance the p10s may overpower the room but I suspect not. Depending on how live your room is, you might wish to cover the rear tweeter ribbon on the p10.
With regards to the tubes option, Calloway has run them on tenors and had no problems and 40 watts of tube power should be fine. They have been well run with aloia amps which have only 30 watts out (though this probably underestimates the power of this amp). I ran mine with solid state as do a number of friends and they are certainly not averse to this, but I have a tubed preamp. Seeing that you will be going with a syrah you might consider ss.
Can't help you about new england but if you are travelling I might have some suggestions. You are always welcome up in Canada but its a long drive.
With regards to looks, they are stunning in my and my wifes opinion especially in the black piano. In fact that was her sole criterion for letting them in the house. They are like lacquered jewel boxes, understated but very elegant. You can see some pictures of the p8ltd and my new c8ltd on this site. Depending on your decor, and finances the c8ltd are every bit as beautiful if not more, disappear more visually and sound even better. The piegas won hands done in the looks department over avant gardes (my wife threatened divorce).
I must qualify everything by saying that when I bought these speakers I had no affiliation with any company but am now very happy to be representing piega in Canada (my daytime job remains being a surgeon - its a long story). I hope this is of some help, if you have any questions drop me a note. Good luck
Gary