Yes, Pugilist can wear Brigand's Acton - and it's incredibly easy to get one lol.

After Fists of the Sixth Sun I went to Boarskin Himantes (like suggested above) and then I don't really remember to be honest... I solo with Disabling Bahanahks (sp?) occasionally for the Paralyze and I currently own a pair of Jade Hora +1 for everything else.

Eternal Shade wasn't around when I ranked PGL but I skipped straight to Toadskin Harness. I picked up an HQ1 for that too. It was pretty cheap on Besaid, I'm not sure what the prices are like on your server. As far as replacing your body piece (or any armor for that matter) it's more or less dependent on your playstyle. If you're just doing DD you could probably use Brigand's Acton and do the Concussive Blow II -> Victimize thing. I wouldn't suggest wearing it for any form of tanking though.