coolant in the oil and the smell of antifreeze in the exhaust is definatly a sign of a blown head gasket or something even worse

yep brewski is correct, using a cooling system pressure tester will tell the tale quickly. I used one religiously to find leaks etc on problems like this. It's the quickest way imo as well.
Also if you decide to pull the head be prepared for an ordeal reinstalling it, the torquing process is time consuming having to torque, run engine de-torque , let cool, re-torque and... it's really annoying but the proceedure is imperative to do as they say or it will fail if you don't. The wonderful part of dealing with aluminum heads and cylinder sleaves.

Once you determine what the problem is your decision from there is going to be wether to fix it or just replace it with a reman engine. If you don't want the hassle of the process of the repair the reman engine might be your quickest and best way to go.