Problem with my 3.1 Heads

I have a 2003 Malibu that recently had a problem with a rocker arm bolt on my head stripping out.

I opted for the Heli coil repair instead of replacing the head.
My mechanic told me that I had a 50/50 shot of it staying because of the aluminum head.

Well 3 months latter the Heli has broke, and the bolt has stripped out again.

My questions are;

Can the Heli be replaced ?
Can the head be retapped for a larger size bolt ?

With 130,000 miles on the car would it be better to get a rebuilt engine or to replace the head ? Looking at the cost I would almost rather spend the extra cash for a refurb engine then risk blowing head gaskets on the other side of the block once the new one is put on and that side of the engine is all tight, bescides it does have alot of miles on it.

Any information is appreciated.

Would you be doing the work yourself? Used heads aren't that expensive, and you can have them checked out, planed, etc. from a machine shop for a decent price as well. Not sure what engine you have, but assuming you have a 3.1 or 3.4L you should have pretty good luck with the rest of the engine if you replace heads/gaskets.