I’ve only ever set one up with trees, so I can’t help there but bear in mind there’s a lot of force going through it, and you really don’t want it pinging out when you’re walking on it. This is especially true if you’re using a 2″ rachet strap one, they’re pretty heavy and sharp.
Not sure what kit you’re looking at but I’ve used a couple and much prefer to tension a 1″ line using karabiners rather than a 2″ ratchet. It’s a bit trickier to set up (but you’ll get the hang of it soon enough), you won’t get it as tight and it’s possibly a little harder to get the hang of, but once you do it’s a lot nicer to walk on, and more fun too.
I was never brilliant (and I’ve not had mine out in ages) but I could walk forwards and backwards, pivot, crouch and I was starting to get the hang of surfing (which is much better on a dynamic line with no ratchet) when I fell off and borked my foot and got scared.