I have not used a crossbow with optics. Can you give us an idea of your optics budget?
The Excalibur uses a Weaver style base so your options are many. I would look at the Burris FFII 2.5x20. It has 55'/100yds. FOV and has pretty good lenses. This scope will be good for low light hunting at bow ranges and is very sturdy. It will certainly handle the shock of any release.
I don't know of any scopes with ranging/multiple cross hair reticles that would fit your description.
I would also look at the Aimpoint CompC3 that ufriend suggests. I have had good luck with Aimpoint regarding reliability. The C3 comes with a ring and since eye relief is infinite you could mount it in any of the base cross slots.