A 13-29 is a great option - I use that with my compact and can climb just about anything. If you switch to a Campy triple, you'll also need a new bottom bracket along with a new front derailleur. A compact is a great place to start, and since cassettes do wear out in time, next time, try the 13-29, or just do the swap now, since it might be time for a new cassette anyway.