First off ... this is not a thread about discs vs rim brakes. if the OP prefers discs, for any reason, then discs are better in this one situation.
Second .... the issue here is Not brakes, it is riding position. As only few posters have mentioned, the bike you buy is not the bike you have to ride forever.
Bikes are tremendously adjustable. There are shorter and longer stems, stems which rise at different angles, even adjustable stems so people can try different positions.
Same with handlebars. There are straight bars, swept bars, risers, flat bars, Jones bars, H-bars, trekker bars ..... and then we can talk grips.
Sometimes a grip can be too fat, or too soft, or too hard .... a lot of people find a really soft grip wears out the hands because the person is always squeezing harder, looking for a more positive hold. Some people are more comfortable with shaped grips.
Talk to the bike shop about swapping in different parts .... they might have some spares and take-offs they could loan you for a test. Or buy some cheap stuff online and try different things. if you have found a frame and fork and wheels that suit you and only the cockpit is a little off ... as one poster noted, make sure the bike is the right size (some shops will sell you what they have and Tell you it is what you need.) if the frame fits, the stem, seat and bars and grips are fairly cheap and easy to change.
EDIT:
One thing. have your husband sit on the bike---I like to lean against the washer-dryer on one side, and have my other foot on my toolbox, but i doubt you would want to come to my house---you can find your own set-up. Basically, you want your husband to be sitting on the bike but with weight on the pedals, not just sitting on the seat--more as it would be as if he were riding.
Then have your husband reach forward the amount he thinks would be comfortable and see where his hands, arms, and body naturally fall. I know I can ride a flat, straight bar if I keep my elbows out a little---which is fine if I am riding tough trails with a lot of dramatic direction changes but can wear on a flat, easy ride. bars that sweep back---angle towards the rider in a slight V---let me drop my elbows and tuck them near my body, and can fit the angle at which my hands then aim.
if he seeks a relaxed riding position, ... or aggressive ... have him mimic that position on the bike and see where his grips need to be Then buy a stem and bar that put his grip[s where his hands are.
A final note----trekker bars (which extend out in big open loops) can offer a wide range of hand positions so a rider can bend low, sit up straight, or somewhere in between and be supported.
https://www.ilovebicycling.com/trekk...you-need-them/ https://sheldonbrown.com/deakins/handlebars.html