What evidence do you have that coolant is really getting into the combustion chamber?
Unless you're dead certain, it might be worth doing some more tests before you do any engine surgery.
One of these should give you more information about the problem:
Compression test- If it's leaking, there will be a certain loss of compression
Coolant Pressure Tester- Might be available for rent at an autopart store
Exhaust Gas Analyzer- It'll let you know it you're burning coolant for sure.
Oil Analysis- It's probably also getting into your oil. Wouldn't be a bad idea anyways, just to detect potential problems with an engine that you're personally familiar with.
All of these are cheap things to do that will at least give you real reason to suspect an engine rebuild is in the works. Who knows, maybe it's just some bad valve stems seals and a small coolant leak somewhere?