I ended up settling on the Astora greatsword. It's the lightest of the Ultras but specced heavy it still does pretty good damage and has great thrust attacks, with a sweeping light, so that's pretty good. But it's pretty clear one handers are the way to go until Poise gets fixed. I'm thinking of doing a dex/caster build, just have to find the right weapon. That will be next playthrough though.
I'm in the Smouldering Lake at the moment, and around level 50. Done some pvp but only against bads with no health, so they get smashed. 27 vigor with the Life ring nets you about 1320 hp, for a pretty small investment. Planning on putting 3 more points in, should go to 1450 or so.