The Aces are not weatherproof, like most the coils are waterproof but the rest of it has no extra weatherproofing whatsoever.
That F22 does, extra sealing all around and tested not only in heavy rain but actually dunked and left underwater for about 1/2 hour.
They won't come right out and say waterproof but if your hubby is going to be around or in shallow creeks and rivers a lot all I can say accidents happen...
Your warranty is null and void if manufacturers see evidence of water damage on units that are not officially weatherproof or waterproof.
If he hunts mostly on land away from water most anything should be ok, for years many of us use regular detectors and maybe out a plastic bag over the electronic and battery parts in case we get caught in heavy rain.
I can see where you can get confused, you are listening to several different people with all kinds of opinions about something you have no clue about and trying to buy decent equipment for someone else.
Here is the deal....
When we enter this hobby one of two things happen, we stay in it or figure out soon enough this is not fun and something we feel like doing so we get out.
That first one is important...a bad working tool can drive you out quickly if it is too frustrating to work with, a good working detector makes this hobby fun and rewarding.
If we stay in it is rare that hunters buy their first one and just use it forever, especially if it is one of the lower price the starter range models.
We all learn and gain knowledge and eventually understand all about brands, models features and benefits available to us and if we want to upgrade we know which way to go for our next one.
Some upgrade pretty quickly but others wait awhile, maybe years, before considering buying another if they picked out a good one as their first.
As far as accessories yes, it is nice to have the best highest quality toys and extras but they are not needed at first.
Headphones...definitely I suggest them but real expensive ones are not necessary just starting out in a budget.
Most packages that have them are usually pretty cheap, something you can buy yourself at lots of stores or online.
I use $100 or so quality phones, now, but in the past I have used and still sometimes use cheaper ones like $25 and under plus earbuds.
I needed some when I went in vacation so I just stopped into Wal-Mart and spent like $15 on some cheap Sony headphones...not the greatest but they worked fine and helped me find stuff.
You need an adapter most of the time to use regular phones on metal detectors
and that is a couple of bucks at most.
Those Sony phones I bought actually had an adapter in the package.
Diggers, I have nice ones now, hand diggers and small shovels, nice to have and use but not necessary.
I started with a $5 hand digger from Home Depot, I have really tough soil that kills most hand diggers around here but even the cheap ones last for awhile.
Handheld pinpointers....these are used to find metal targets in the holes we dig and hiding in the dirt we pull out of holes.
VERY helpful when you are new and indispensable for many veterans.
I won't go hunting without one, not fun for me.
Again I have nice expensive ones because they just work great but cheaper ones work too, a lot of them, anyway.
Not as well as the best ones but they work and I started out with a cheap one from Harbor Freight and it was fantastic....1000x's better than using nothing for sure.
https://www.harborfreight.com/metal-detector-97245.html
Basically buy the best bang for the buck detector and don't worry about accessories because the cheap stuff works pretty well and can be upgraded.
Beware of package deals that have a lot of useless stuff you don't need or contain things like headphones that you can buy aftermarket that are as good or even better.
I like Fisher detectors, great quality and very capable and a nicer screen than that Ace.
High quality, actually weatherproof and great to learn on.
Call a few dealers that sponsor the forum and ask what else they can do for you, free shipping is usually included but what you see online isn't always what you get...they can deal.
Not much room to discount or add in a whole lot of decent accessories at starting unit level price points but you can ask.
https://www.bigboyshobbies.net/fisher-f22-metal-detector
This is Bart at BigBoysHobbies, I have dealt with him in the past as have countless others so maybe start here.
I used an old version of that F22...an F2, if the same DNA is in the new one you can do a lot worse.
Start with a decent name brand tool for a detector like the Garrett and Fisher you mentioned.
Don't worry about top of the line accessories at first, a trip to a hardware store can get you decent, cheap tool pouches and diggers, cheap useable headphones are everywhere.
If I lived in an area with the large possibility of rain anytime and especially if I was going anywhere near water I would choose the F22 and it's extra protection...plus for how well it works for a detector in your price range.
Waterproof detectors are even better but way out of your price range...for now.
Good luck!