aicmichael, the 1.8 is a breeze to maintain. Quick question: are you going to leave it in the water, or trailer it?
For maintenance, you'll want an oil change kit for the 10-hour service, and then once a year thereafter, assuming you don't put on so many hours that multiple oil changes a year are needed. Also consider replacing the spark plugs once a year. A little grease for the intermediate bearing, some Salt-Away, corrosion inhibitor spray to protect the metal bits, and you should be good to go for many years to come. I guess upgrades would be the one thing to think about.
Pros: super easy to maintain with minimal parts and fluids. Inexpensive relative to other drive systems, simple, reliable. The 190 is economical on gas compared to a 5.7. The draught is ridiculously short, so you're less likely to damage anything on underwater obstacles.
Cons: it's a light boat, so if seas are rough, you're going to be bounced around and the pump may cavitate because there's no outdrive hanging in the water. Also, jet drives don't like sea grass (not sure if that's a problem where you are). Compared to a 5.7 sterndrive the 190 will feel under powered.
There's really not much to maintain or break on these boats, so stocking parts isn't much of consideration. Oil filters, spark plugs, anode for salt water, and fluids. That's about it.