Sharon
As a 40 year in the trade my experience tells me you should buy a nylon stain master carpet. A 70 oz carpet is too much nylon on a set of steps unless you prefer sliding down them. I would go no more than 40 oz about 1/2” high nap. Too thick of carpet tends to corn row and looks terrible after awhile. I also would suggest a nylon nap pad on the steps this will wear better and as you use them they won’t cup in the middle like they will with foam pad. This type of pad also will reduce slip-age on steps and be more firm to step down on. I would hate to see you fall or slide down.
Pad for the rest of the areas should be dense but no higher than 1/2”
All carpet should be power stretched to wear the very best. If they just kick the carpet in this will be very bad after about a year.
Q
Curved stair idea
Q