City Motor Supply had a good recomendation by Sam the Isuzu Tech who has disappeared. In reality, any shop which can do Metric/diesel engines can do our engines. (if they ONLY have chevy 350's then I would keep looking). Below is everything sam did to his trooper's engine. I hope it helps.

Here's what Sam said in a different thread awhile back with regards to the 2.6L rebuild:
-cyl. head is out of a 95 2.6 witch has a smaller cc. chamber ( area around the bottom of the head is smaller)
-had block bored 1mm over size about $48.00
-crank turned .10 due to wear 215,000 miles $78.00
-rod and main brgs. around $125.00
-valve job on cyl. head done this my self. mach. shop would cost
around $60.00
-gasket set around $125.00
-1mm over size pistons with pins and rings $175.00 with shipping from http://www.citymotorsupply.com
if these guys don't have it you cant get it. this was the only place that had the pistons.
-.260 degree cam from www.deltacam.com $49.95 for reground cam plus
$30.00 core for old cam
-k/n filter from auto zone $35.00
-header from claimni around $206.00 with shipping
-2 1/2 inch exh with out cat and 2 stage flow master from header back $168.00 can not tell you where i got this put on. The exh. is a little louder then i wanted but it is on now, kind of got used to it.

-other fluids,filters and i also replaced all hoses with new factory hoses
around another $100.00