If you can find an automotive oil filter that will fit your engine you
can save a few dollars since the auto filters are sold in much larger
quantities which drives the prices down. Get the largest (longest) one
that fits. The extra size means extra filter capacity, and additional
cooling surface.

Make sure the threads are an exact match - don't use a 20mm thread on
an engine that wants 3/4" thread. You can tell if there's a mismatch
because the filter will be loose and wobbly as you are spinning it on.

I'm told that the SuperTech oil filters that WalMart carries are
actually pretty good quality. And they're only 2 bucks each. Chances
are there's one to fit your engine.

Just make sure you change the filter before it clogs up, because the
bypass valve pressure setting may be wrong if it's not an exact match.