Sounds doable. The long cage rear der will work but shifting will be a little slow. The bottom bracket is probable too long. I'm not sure about the front der. It should have enought travel to make the jump but you will have to adjust the limit screw so it doesn't jump off the chainrings. If the bike is Shimano the left shifter is indexed and might not shift well with a double, Campy doesn't have that problem. You are looking at a new crank, BB for sure and maybe new derailluer and left shifter. Try out the old parts first before you buy. Shortening the chain is a snap.
Tim