Quarantine

I'm planning on going to buy some clown loaches tomorrow. Well,
probably clown loaches - this is my eldest's choice; we'll look at
the yo-yos and zebra loaches too, and I'll explain the pros and cons,
but in the end, it's his birthday money, so it's up to him.

Anyway - the store we're going to says they quarantine all their
stock for two weeks before selling it. In that case, do most of you
still quarantine after purchase?

If we're going to quarantine, how long would you quarantine for? If
we're doing that, I'll be filling my 60-litre tank tomorrow morning,
and putting in the heater, but I won't move the filter across from
the 125-litre until we get home with the loaches. I know a 60-litre
isn't big enough for three clown loaches long-term, but it would be
adequate for quarantine, wouldn't it?

I've never quarantined anything before - what should I put in a
quarantine tank? I assume gravel - not a problem, I've got spare. I
know clowns like to have hiding-places; should I pick up an extra
rock or two to provide that in the quarantine tank?

Anything else I should know?

--
FishNoob