Messing around with the mistubishi calculator (google it if you're interested, very useful!), it seems that to get a 96 inch screen that is 26 inches above the ground with the HD1000U (and no keystoning), you need to have a 1.5 inch drop from your 93 inch ceiling. If you can find a mount with this little drop, that would be a nice solution. If you had a 3.5 inch drop, you could get a maximum of a 93 inch screen... not a huge difference if you can add a little black velvet around your existing screen.
Can't speak for the HD70 unfortunately.