I use 'baby' carabiners in exactly the way you propose and they seem to work fine.
Those 'Quick Links' with the threaded barrel are probably overkill for a tarp, IMO.
Something like these would probably work OK- I've used them for my tarp.
These are a bit stronger and definitely work for a tarp:
Both from diygearsupply.com, but you can probably find them locally....