Aether can be a rare harvest in Kelp, transmuted, and many plants drop it as well (Evil magma peas). Try Crab alley or any underwater area (Celestia has one). Bazaar is easiest, see my post under the diamond thread. pods
I also have this quest. I got lucky and picked up two aether harvesting kelp in Crab Alley. Best place I found for kelp is Crab Alley in Wizard City. The Grotto in Celestia is another place but it takes a bit longer to get to. I have been harvesting kelp and will probably transmute to aether. I might try planting some Evil Magma Peas like pods1973 suggested. I hadn't thought of that.
I haven't had any luck gathering sunstone either. I keep watching the Bazaar too. I'm also gathering stone block to transmute to sand stone and then sand stone to sun stone. Not the fastest but it is effective.
Have you been able to find where to get some conga drums? I've been everywhere and haven't found any.