I have had a 10HT for about 4 months now. I too am unable to mount it to the ceiling (also unwilling to pay $300 for a mount). I made a mount out of a wood platform and wood braces for about $30. It is 12ft away from a 108" Draper screen 1.3 gain. Works very well.
I would recommend against getting one as big as you can. If I could do it again I would get the Stewart Grayhawk roughly 90" screen instead.
The digital keystone will correct the problem if the projector is not on a true flat surface. But it was frustrating enough to set that I just made sure the mount was level. With a 10-12' throw, you should be fine for at least 72" screen. Let me know if this helps.
I would recommend against getting one as big as you can. If I could do it again I would get the Stewart Grayhawk roughly 90" screen instead.
The digital keystone will correct the problem if the projector is not on a true flat surface. But it was frustrating enough to set that I just made sure the mount was level. With a 10-12' throw, you should be fine for at least 72" screen. Let me know if this helps.