My 85 Westy (auto trans, AC) has 150k miles on it.  Just had the oil
changed and the mechanic said there was a lot of metal in it (both
brass and aluminum).

It also idles very poorly and has low oil pressure.  My mechanic
thinks that the poor idle is caused by the low oil pressure (lifters
not lifting?).   I just replaced the AFM, which didn't seem to help
much.  One of the heads leaks coolant (slowly) to the outside.

So I'm thinking it might be time to bite the bullet and get a new
(rebuilt) engine.   Advice on this topic is appreciated:

Question (1): If I decide to put another 1.9l in, I've found three
places to buy:

   $1750 at BusDepot
   $2300 at BostonBob
   $2990 at GoWesty

That seems like a wide price range.   Anyone out there have
experience with a rebuilt from any of these places?  Are there other
suppliers recommended?

Question (2): What would be a reasonable cost for a mechanic to do
the engine swap?

Thanks
-mike