Looking for Oregon maint. shop recommendations

We are looking to replace the run-out Lyc. IO-360-C1C6 engine on our '79
Piper Arrow IV within the next couple of months. There is nothing really
wrong with the current engine, other than it leaks a bit of oil, but its
time is beyond TBO and we are rather conservative owners.

For various reasons we are leaning towards a factory overhauled or
remanufactured engine or an engine from one of the "name" shops like Penn
Yan. Between the cost of the engine, the installation, and associated other
parts and labor we are looking at a LOT of money. The plane is based at PAE
near Seattle, but it occurs to us that we could save maybe a couple thousand
bucks by having the work done in Oregon where there is no sales tax. I
would therefore welcome some recommendations on shops in Oregon, preferably
somewhere around Portland or Eugene, that can be counted on to do quality
work at a fair price.

Yet to be resolved is how the exchange engine is purchased. Most shops will
actually want to deal with the engine vendor themselves and mark up the
price to us by maybe 5-10%. That's quite a bit on a $20,000 engine.
Naturally, we'd prefer to deal with the vendor ourselves (for purposes of
purchase) to save this markup. Any experiences or insights on this
situation?

--
-Elliott Drucker