Aaron-
I tried the 9000 series device perhaps 2 years ago and it was good. I was just tryng it out at home so I do not have any experience with setting it up and using it over time. But it looks promising.
No problem with rear delay-fill loudspeakers being ceiling types provided they are aligned and equalized to blend with the primaries.
The EAW L8CX2XO is a 8" coax ceiling loudspeaker that I and a few of my peers across the US have found to be an exemplary device, with great polar response including through the crossover. They're $175. list each, so may not fit your budget.
I find that there are very few bad ceiling loudspeakers this day provided you don't go stupid cheap. EAW Commercial and JBL Control 2000 series are two that I use often and like quite a bit. They come in different sizes and power ratings. Even the Bose ceiling devices work quite well and have the benefit of utilizing no crossover.
I have used column loudspeakers for 2 lecture hall systems I have designed and with very good results. The Bose MA12 is by far the most compact and least expensive. If it is a larger, reverberant space use two MA12's (stacked) for greater vertical pattern control down into lower frequencies. I also like the Frazier CAT 2x7, which costs a bit more but is a more complex design (has 7 woofers with 7 tweeters that are in an array at the middle of the enclosure (in front of the cntr woofers) and therefore exhibits smoother response). They will build a bass extension module (same size column w just the woofers) for you to enxtend that line. If either of these systems needs to reproduce music I add bass modules such as the Bose MB4, which often can be sat on the floor below the column(s).
I find that the column loudspeakers are easier to fit (physically and visually) into such spaces and they have several other attributes. If the floor is raked/stepped (most lecture halls are) you need to determine that the columns will cover well from the height you can mount them.
The alternative is to use small format 2-way "point source" ldspkrs and various candidates would be the EV Zx1, EAW JFX88 or the JBL Control 28. These can be suspended from above or attached to the side walls.
All of these surface mount loudspeakers come in white or black and can be painted. The column ldspkrs are trickier to mount (especially if you use two stacked devices) and the surface mount ldspkrs are comparatively easy (they all come with well-designed ball & socket pivot arm hardware).
All optimization functions are available in the TOA (or other) DSP. I pay as much attention setting up these systems as I do with larger church and performance systems and if they are completely optimized they work very well with greatly reduced feedback potential.
HTH