Acrylic is is pretty good & you can get a satin variant from supercheap. I've used it on several builds. For a really nice satin finish that is extremely durable I find it hard to go past Cabots Marine Grade Polyurethane, available at Bunnings. It's around $20 for a can, but that will be more than enough for a body.

I did this one in that product, but I had also done it in gloss and blocked it back before hand so that no grain is apparent. Some deeper cracks were filled with CA as well.



This is just a can and no grain filling, but several coats over a few days.



This one is using the same stain as the top one and no grain fill because I wanted to show the weathered wood a bit more.



And this is the product itself

https://www.bunnings.com.au/cabot-s-...-pack_p1520268