I havnt heard one mention of the proper way of removing a busted head bolt...ANY EVER HEAR OF AN EZ-OUT. They are reverse threaded steel bits that get tapped into the remaing bolt, and simple turn counterclowise, they will drive themselves into a hole drilled into the busted bolt, and once tight enough, it will beginning spinning the bolt out...anyone...anyone??...I worked on aircrafts for 2 yrs, this was the only way we ever did it, 100% satisfaction garunteed.
Auto parts stores sell little manifold repair clamps that can get you up and running right away--kind of like a little c-clamp that will clamp the header flange to the x/h-pipe flange. Pretty? No--but it will get you on the road fast and cheap while you figure out to do in the long run. Personally, I'd just find a set of unequal shorties and replace the stockers but that takes some spare $$$. Good luck!