Did another manufacturer pick up where Ares left off producing this kit?

Looks like Fight Lite has taken their webspace and dropped the piston side.  It's not surprising, because there are several systems that have a simpler mechanism.  Probably cost prohibitive to produce and sell.

Superlative Arms has a kit. Don't know if good or not... haven't bought one.

https://suparms.com/collections/retrofit-piston-kits

There are kits on the market.  I have Superlative and Adams Arms.  Both have pros and cons.  The cons are small, but there are some things.

Superlative is better at compatibility across handguards.  Basically if a low profile gas block works, Superlative works.  Adams Arms get's tricky mostly because of the barrel nut.  The Superlative piston/spring is contained in the gas block, so the only thing that extends to the receiver is the op rod which is the same diameter as a gas tube.  The AA has the spring on the op rod at the barrel nut, so it has to be able to fit there which means no unusual barrel nuts.

Adams Arms:


Superlative Arms:


The AA kit is a little more simple in construction which means it has less to go wrong.  It's also "self cleaning" which means less maintenance.  That can be a good thing if you don't want to keep removing and re-installing your handguard.  It still needs it, but not as much.  I've never cleaned one of my AA pistons and it still runs fine.  The Superlative get's a little dirtier in the piston area and needs to be cleaned, but like every few thousand rounds.

Both have adjustable gas blocks, but the Superlative is way more adjustable and has a bleed off feature that the AA doesn't.  But still the AA is tunable.