I love my Greenworks 21" self propelled 60V. BUT, I discharge the grass out of the side & have never tried to bag it. I have the mower, string trimmer, blower, hedge trimmer, chainsaw, & power convertor, so you see how much I like their products. Are you sure you only have 7000 sq. ft...
I used to have a yard with a few sloped areas that were similar. I also had to sit on the upper edge of the seat & lean. My wife could mow it without much trouble, because she was much smaller than me.