Ritchies was assimilated into the Bevie group in 2020. Bevie are based in NZ and distribute Grainfather and Mangrove Jack among other well known names. That doesn't mean it's an MJ yeast though. A kit yeast should do the job as invisibly as possible to the user: temperature stability, no funny smells, quick to drop out when done and then stick like glue to the bottom of the bottle. Something like Muntons Premium Ale yeast, repackaged, of course. Bevie are also distributors for Muntons in some parts of the world.
Remember that kits are made to a price. Kits that require added sugar are much cheaper than those which offer the full weight of malt extract because sugar is very cheap in comparison.
If you're going to add DMS instead of the sugar, you might as well buy a full extract kit to start with.
MOST IMPORTANTLY: WHAT DOES THE BEER TASTE LIKE? IS IT ANY GOOD? I've seen some decent reviews for the Simply range.
It has been a long, long time since I made "single tin" kits, but, in my experience, the stouts were always the most successful.