Judy, meaning no offense but have you & the hubby really talked over the need for an
autopilot at all? When properly trimmed, if properly designed and rigged, a sloop like this should be able to hold her course with no one on the helm at least in good weather and calm seas. An
autopilot isn't going to hold in anything much stronger. Which begs the question...Why bother at all?
Someone has to be on deck at all times (except perhaps for very short periods) to maintain a watch while you are in motion. Folks sometimes don't--but legal standards all over the world call for keeping a "proper watch" at all times. As long as you are there...so you watch the wheel and set the wheel brake to help hold the rudder centered, or you steer a little. No big deal. World cruising and crossing empty open oceans...the autopilot becomes more important. I don't get the sense that's what you intend, though I may be wrong.
But more so, why go half heartedly? Hunter has a reputation for being a beginners' boat, which is NOT a bad thing since it makes sailing affordable for many folks who just couldn't or wouldn't invest in something like a Hinckley or Sabre. But when you start to look at resale value...well, I'd say that investing in any autopilot could be a total loss at resale time, if the buyer is looking for a budget boat.
On the other hand, if an autopilot impresses them...I'd guess they'd pay more for an invisible installation and a more robust grade of autopilot. Below deck.
I'd go whole hog, or no hog at all. But that's just me, and your mileage can and will vary. I'm sure!