As such, I'm doing some research before taking a trip up there to sniff around.

A trip to Stockton today, drove by a couple of areas where the few properties located.

My advice if you're going to buy a multi-family from the MLS using your VA loan, as @Joe Funari suggested, shoot for a trip-plex or a quad, and negotiate hard on the price to ensure that you don't over pay for the property (even if you are buying it off the MLS).  

Driving 4 hours round trip to save $180 per month does not seem worth it to me.

Next day post would be much cheaper and I would think posting a letter should be covered with the PM fees.I only have professional PM on our STRs (No experience dealing with LTR PMs) and they are not cheap but they also do not charge us for trips to help the STR tenant with things and certainly not for phone calls or to post letters. 

Note that the NEC now requires a GFCI for refrigerators but many local inspectors allow you not to do this because if the thing nuisance trips, all the food will go bad.

I'll have to plan a trip there soon to get a lay of the land. 

There was a recent post here about a guy complaining about how much his property manager charges to send a letter, $45, 20-some posters chimed in that it was crazy and a rip-off, and then finally one of the most experienced property managers here explained that the price charged really involved personally sending certified mail from the post office, actually scheduling a trip involving the inevitable waiting period for getting it done, tracking the return receipt, logging all the information for use later in court if necessary.

They are all close enough for me to drive (no more than 10 hours) or $250 dollar round-trip. 

There are attorneys in many markets, mine included, who search forums like these and hire college students to call properties listed for rent in an attempt to get a landlord to see if they can trip them up, just looking for someone to prosecute.