Celestron makes a number of spotting scopes that will do the job, but I recommend that you go with one that uses Maksutov-Cassegrain optics.
Most spotting scopes are refractors. That is, light is transmitted in a straight line from the object of interest to the eye, through a series of lenses. Same thing with rifle scopes.
Those that use Maksutov-Cassegrain optics are reflectors that use concave ground mirrors to magnify an image. Until recently, good reflectors were expensive, but the Maksutov-Cassegrain system, along with computer controlled machinery to grind the mirrors, brought the quality up and the prices way down.
The advantages of these scopes includes small size, incredible power and resolution, and VERY bright optics. No standard spotting scope can hold a candle to them. They can easily spot .22 caliber holes at 300-400 yards, even in low light.
The down side is that they are generally more fragile and they aren't (to my knowledge) nitrogen filled and sealed, so they're more prone to fogging.
I have a Meade ETX series telescope that uses the Maksutov-Cassegrain system, that cost me roughly a thousand bucks. The same quality and power telescope would have cost around $10,000. thirty years ago.
Even with the disadvantages, I don't think you'll regret going with a Celestron spotting scope that uses the Maksutov-Cassegrain system.
