Home wiring question - light circuit

I have some pretty awful wall lights in my house which sit above a media case, and another above a book case.

I want to potentially replace the ones above the media case with led strip lights, and the ones above the book case with some downlights. Ikea stuff is fine for me - so the likes of the dioder or omlopp from here http://www.ikea.com/ie/en/products/lighting/integrated-lighting/.

They're both designed to plug into a mains, and have the transformer built in. Anyone know what sort of transformer I should use to have these hardwired into the lighting circuit instead? Presuming they wont be drawing huge power so shouldn't be an issue on the light circuit?

I have IKEA led strip lights in the kitchen I just cut off the plug top and used connector block onto existing circuit. Transformer is retained
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Hope that made sence?