Dont install halogen downlights. Install these instead:
Much better, in every respect. I'll be buying some myself when I do my kitchen. You can buy a white frosted glass trim, so you wont even know they are there! They require a 15cm cutout, but thats because you get much more light from them, than a halogen light, and you'll only need half as many, if that. Ignore the price on that link, they seem to have screwed up their website somehow - the price on that page is for the emergency version, the standard one for 2 x 13w is about £22.