19 ft from a 92 or 100 inch screen is an aweful long way away if you are looking for the theater experience a projector can provide. The usual rule of thumb is viewing distance is 1.5 to 2.5 times the diagonal size of your screen with higher resolution projectors and blu-ray easily supporting the shorter viewing distance.
I've never viewed blu-ray, but if you are going that route and watch lots of movies then going with a 1080p projector will likely give you a noticably better picture than a 720p projector as you are using the full capability of the former (assuming it produces comprable black levels, lumens relative to room darkness and throw distance etc.).
