They're ok for canning, I just wouldn't trust the lid for repeated opening / closing. Get extra lids, and keep an eye on them as you use them. Only use lids with gaskets, if it's a choice.
Edit: Is something like this available to you?
http://www.amazon.com/Bormioli-Rocco-Fido-Storage-Jar/dp/B0028UHDG4
I use these or something like them. I admit, a lot of my 'open' collection sits in plain old mason jars as well.