I've got a Ladle as Vickster suggests and it's good.
However I've also had softer gel fill saddles which some discount as not so good for the undercarriage for some reason.
But I've been fine on one of those too for general riding, and multiday tours as well.
For years.
I'd say let your good lady wife take charge of saddle procurement herself.
It's a very personal subject, and I'd personally not want someone else making those decisions on my behalf.
However getting buttock bones measured would be a good start
My mid market bike shop has got one of those things you sit on to get the measurement.
135 mm as it happens