A question about replacing toilets, part II

You have helped me a lot earlier so I have a follow up. No, have not got the new ones yet.

Yes, decided on Kohler Santa Rosa, elongated. I measured the space above the floor and they can fit.

But... what about below the floor? If the elongated one is larger will it be possible to fit it into an area surrounded by wood in one place and linoleum in another? Though I do have a good plumber who does think outside the box.

Another question. In the old days, when flushes sent gallons of water into the bowl, a plugged toilet would send the water on the floor. Thus, every place that I lived I - meaning a plumber - would install a quarter turn on the shut off valve. On two of them I turn the valve to the side. But on the third I have to turn it forward.

I turn the valves off when cleaning the bowls to get below the water line; we have hard water in the city. I don't have strong fingers and it is difficult for me to turn the valve forward, especially in the tight spot.

Will it be possible to switch the valve from a forward movement to a side one?

Thanks. Appreciate all the knowledge here.