Other than Bus Depot and Vanagain, both of whom have been great to work
with, try your local FLAPS.  I ended up with a rebuilt 4 years ago for
my '85, cost about $125 (cheaper than anyone else, who were in the $200
range). (This is from Auto Palace, which is now Auto Zone)

Never had a problem with it.  Just before I sold the '85 I had a battery
problem.  Pulled the alternator have it checked.  Auto Zone checked it
ok, and had another  rebuild on the shelf. While playing with the
pulley, we both noticed a ever so slight 'squeak' of the bearings.  The
salesman comment 'take the new  one, you have a lifetime warranty
anyway!'

So, 3.5 years on a  rebuild, which checks out ok in all respects, and I
get a newly refurbed one any ways.  I couldn't fault the price or
warranty.

Good Luck

Scott
'90 Vanagon Carat