We have had a wonderful GE Profile microwave/oven combination since we bought our house. We recently had to repair the microwave and I found out that GE makes over a dozen different magnetrons to fit various models of microwave. Ours had a very powerful one that took only a little over half the time to heat a cup of water than any other microwave I have owned. My daughter has one too as a single and it is very fast too.

I don't know if they make an oven to fit over your stove but I highly recommend the inverter microwaves that Panasonic makes. These ovens have true variable power, unlike normal microwaves. If you select 2 minutes at 50% power you really get 50% power for the whole 2 minutes, Not full power for 50% of the time. I am not a great cook but I can cook fish perfectly, steam delicate veggies and melt butter with no mess.

I think Panasonic is the only company that makes them but they sometimes show up with another name on them.
I have a small one I got at Costco for $100, but there may be fancier ones available other places.

1) Sharp
2) Panasonic
3) Samsung

These companies make and sell MWs under their own brand. Everyone else slaps their name on a MW made by the above three or a Chinese/Taiwanese contract manufacture.

BTW. Sharp also has true variable power microwaves.