Hanging canvas pictures flash to (plasterboard) wall.

I have 5 pictures I need to hang. The dimensions are:
30cm x 30cm
30cm x 30cm
30cm x 40xm
97cm x 38cm
117cm x 82cm this one: http://www.johnlewis.com/202642/Style.aspx

Anyway I want them flush to the wall. There are 3 fixings I've seen:
1. 3M command picture hanging strips.
2. Mirror plates.
3. Sawtooth hangers.

But in John Lewis they had these white plastic brackets screwed into the wall with the hook coming straight out at 90 degrees. And I think the hook was threaded.
What are these brackets they use in John Lewis? And what way you would suggest I hang my pictures? I really want them flush to the wall.

These seem like the perfect fixing to me http://www.picturehangers.co.uk/canvas-hanging-products.html

use toggle bolts they work fine with plasterboard and I'm sure your pic's are not very heavy. You have to make a small hole 10mm or slightly more to fit the toggle bolt through. If you hit studding just screw into that with a normal screw.

If you want to find studding in the wall it is usually 16" so measure around 15 1/2'" from the corner of the room and use a small nail to tap into the plaster board to find it. Be carful not to do this above any sockets

Do you mean these by any chance?

http://www.choiceful.com/choicefulsubcategory-L-Shaped-Screw-Hooks-buy-F1-choiceful-18-shop-G10.html

http://www.ameribestfasteners.com/toggle_bolts.htm

and here is a video of how to use them,

http://www.youtube.com/watch?v=_IuNkiiqhO4