Any recommendations? I had guards and found they rattled, slowed me and were less effective than what I wanted.

Honjo or Velo Orange. Aluminum, come in a bunch of sizes, depending on the frame/tires you’re using.

You still might need additional mudflaps on the front to keep the spray off the bottom bracket and rear for others rig is with you.

SKS (also known as ESGE or Blumels) "chromoplast" full fenders have always worked well for me. There are fancier (sometimes metal) fenders, but they tend to rattle, like you say.

This one is cheap and light and works great on various bikes but on a 29er:

https://a.aliexpress.com/_Eu2mwYj

Link is broken, but my curiosity is piqued.

Link worked for me, the item description is "Rrskit Bicycle Fender Ultra Light Foldable Bicycle Mudguard"

For chain and coat guards: Hesling. Plastic or cloth, they're equally reliable. For mudguards, basically anything aluminium from any Dutch maker. If you can get Azor, they're especially high-quality.

The guards aren't properly mounted (or perhaps lack sufficient rigidity & mounting points) if they are rattling and rubbing.

It's worth it to invest in good guards to keep the mud off your bike!