No you certainly do not have to have an A-lens. Here are the options for a 2.35 CIH set up in order of increasing cost:
1. Manual zoom and electronic vertical shift. Zero additional cost.
And no big deal. I manually zoomed and shifted my Panny 700 for 7 years, and it took less than 30 seconds. Of course you have to be able to reach the projector, so you need to shelf mount.
2. Projector with lens memory for instant remote zooming, vertical positioning, and focussing. The Panny AE4000 and AE7000 are the lowest cost of the very few projectors that have this capability. Projector will be in the range of 2-3k. The lens memory feature works incredibly well, with auto aspect ratio switching taking less than 10 seconds, and the projector can now be up on the ceiling if that is your wish.
3. Use an Anamorphic lens. This is regarded by some as the ultimate solution, although as the Moderator has stated, the whole benefits of zooming versus A-lens issue is very controversial. What is not controversial is that the A-lens solution can be very expensive, with the lens perhaps costing much more than your new projector. And there may be additional significant costs such as the need for a sled and even a curved screen. Certainly the top tier home theaters (the ones in the home theater magazines) always seem to use an A-lens.