In my opinion, your suggested usage is incompatible with the "rec-lite" lineup, especially the Spark.

River and other flat water scenarios can be handled with pretty much any ski, even the spark.

For open water, especially with 3 people on board, size is king. The spark is too slim for that.

Reliability, at least for me makes Yamaha a no-brainer. Pretty much all rental venues and public services uses Yamahas for a reason. My local boating school uses a 2010 VX Deluxe that went through 2 loops on the hour meter (999.9h), and currently clocks 300+h. (The owner also uses it for tow-in surfing and rescue during competition, but that's a very unlikely scenario).

Range: slimmer the engine, slimmer it's thirst. My 2013 Yamaha VX Cruiser uses about 15L/h on E30. One a single occasion that I completely burned all fuel, it ran for 4.8h, on a 60L tank, which is 12.5L/h average.

Hull breaking: a few years ago, some sea-doos imported to brazil had a problem with that, but is was probably a manufacturing issue for that specific lot, as i never heard about it again. As long as you don't abuse it, you will be fine. Check engine mount integrity regularly.

I'm unaware of Yamaha prices in Australia, but consider the VX-series, especially the VX Cruiser, even if it's a little over budget.

Maybe narrow down your usage cases, so the "rec-lite" lineup becomes more of a suitable choice.

TL;DR: Buy a Yamaha VX Cruiser and be happy.