Re: EMT conduit handlebars?
As Ilikeabikea said, EMT, no less than 3/4" will work as long as you're not curb jumping or going off ramps with your bike. Reasonable riding speeds and smooth roads will not offer enough stress to be concerned with. However if you're a heavy weight guy and tend to lean on the bars and do rough country riding, I'd opt for something a little stronger. The hardest part is going to be making duplicate/mirror image bends. Getting one side the shape you want shouldn't be hard but making the other side exactly like the first is going to be a challenge, especially if you're free hand bending. Good luck and please post some photos of the finished project if you go the conduit route.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"