I use a
Lindam baby gate on our stairs. Without it, one of my dogs runs upstairs to steal dirty laundry and it's easier to keep this gate shut than get my kids to remember to shut their bedroom doors!
It's a pressure fit one so no screws and it opens like a gate. (I think the one you linked to has to be removed completely every time you want to go through). I got mine on a special offer for two from Tesco Direct.
My gate is fitted on the bottom step, and against the riser, so that it can only be opened towards you as you go upstairs. My youngster would
push a gate open but will not
pull so even we've forgotton to close the gate properly, he won't get upstairs. It's also higher than when fitted on the floor so a baby gate size is fine - a taller pet gate is not necessary.
One thing to watch with a pressure fitted gate - the rubber pressure points can get a bit tacky if left in place a long time. (When we moved ours it pulled some paint off). You are really suposed to screw fit the cup protectors on the wall first but I didn't want to damage the wall - I got round it by using cotton wool pads to protect the paintwork.
An alternative if yours just needs a visual barrier rather than a fixed gate. Orvis do hinged 'fence panel' like ones. These
zig zag versions are quite expensive but nicer looking. I'll bet you could get a handyman to make some for a lot less!