connecting isolator valve to copper pipe

[russellmre]

I'd be really grateful for some help with a DIY project. I'm renovating the spare bathroom. At the moment the pipe connecting the sink to the water supply pipe (which itself is already hidden) is outside, so to make it look nicer I want to bury it in the wall. So far, I have got a groove on the wall, cut a length of copper piping, connected it to at one end to the water supply, and wrapped the pipe in some foam so it doesn't come in contact with plaster, and bent the pipe to shape at the other end so it comes out of the wall at a right angle. I now have to find the right connector so I can put a valve on the pipe where it comes out of the wall, and then I can run a flexible connector from the valve to the sink.
the valve looks a bit like this:
http://www.alliancegb.com/ASProundIsolatorValve.html

My question is what is the best connector to use to connect to the copper pipe to the valve? I found something like this:
http://www.lowcostplumbingsupplies.co.u ... pler-cop...
it's a 12 mm to 1/2" female connector.
The problem is, unless I want the whole connector to be sticking out of the wall (which won't look good) it will be partly hidden behind the tiles. I'm a bit worried about that because once I start tiling I won't be able to access the connector if it starts leaking, I've heard that it's best not to use compression fittings unless you can get at them easily. So what would you suggest, what is the best way to fix the valve onto the copper pipe? Should I look for a different connector and/or valve?

[stoneyboy]

russellmre,
You'll need a 15mm copper to 1/2 inch BSP female elbow, hack enough out of the wall so you can make the joint to the copper pipe and use ptfe on the thread of your chrome connector.
end

[htg engineer]

As you say, it's best to avoid any joints in the wall. http://t2.gstatic.com/images?q=tbn:ANd9 ... kYJ4jtmcq4 Should do the trick.