The Spirit Realm

There's a decent 115 hp shield you can get from DoN vendors for crystals. Don't really know of any shield much better than yours you could solo tbh.

There's also a few attunable secondary items you might pick up in bazaar if you have the pp... from Sewers of Dranik, and from 1.5 final fight epic chests and that drops in WoS from Shadowhunter (1-3 grps) . There's also a priest shield that drops in RSS in basement (althogh it hard to get a group there) . An of course there's the from MPG Ingenuity trial although thats one of the harder trials.

Hope it helps a tiny bit.

If you have a key to Veeshan's Peak, theres a decent quest up there for a 125 hp, FT3 shield with druzzil's distance on it that can be completed solo.