First, good for you to make a nice gift to your Dad!
OK, so you got a grand to spend, like tones, and will be hunting dry sand and fields?
We of course will all recommend what we would use in your situation, and that could make it tough for you to decide. Try to break your decision down into segments if you can, check out the tone capability of machines first, price second, then the rest just becomes a matter of personal preference and small details...
I would suggest you look pretty hard at the F70, and others in that framework, it has Delta Pitch tone capability, and a lot more, DP assigns a different tone to every integer on the scale from 1 to 99. so a nickle sounds different than a pulltab, and a Q from a dime, and so on..
Its very light, so you can cover fields and sand all day, it uses the same batteries as the ATPro, and its under a grand. If you get it with the 11"dd coil and get a 5" along with it, you will be set up pretty good.
Full disclosure, I have an AtPro and an F70, and switching from one to the other covers a multitude of situations be it weather or speed. You can extend the shaft and sort of crouch down and cover a heck of a swath on a beach or open field very comfortably and fast. Well, you got all winter, you may just as well find the nearest dealer and go try a few different ones out. Good Luck, and HH
Mud