Allen, I know this isn't relevant to your current question, but have you considered getting her a riser recliner yet?
As far as mobility in the home.... we have people who have wheelchairs, hoists, or even just a commode with wheels. There are many ways of getting around the home, which don't need electric scooters.
The Minimus Folding Mobility Scooter from CareCo is an excellent piece of kit but pricey. You could always enquire about hiring something rather than buying to see how it goes.
I'd probably be more inclined towards the manual handling type in a flat as Barsel suggests above.
I shouldn't get too sophisticated and particularly living in a flat with your wife's clear disability i would stick with a basic NHS Zimmer frame that you can borrow from Social Services.