I think you'll find Bali's diving to be more rewarding and superior to Thailand's.
I agree with everything Luko said.
Sanur is only worthy of a sleep if you plan to dive Nusa Penida. Kuta is tourism ugliness at its best
Padang Bai has always felt a bit dirty and shady to me for some reason. I would never choose to stay there instead of closer to the best dive sites for a few more restaurants. Nothing there is that good!
Someone will probably jump on this post to persuade you into a dive safari for Bali, but it sure sounds like too much hassle to pack/unpack every day & sleep in a different place every night.
There is enough to do topside in the Tulamben area unless you need boutique shops and malls. The nearby Tirtagangga Water Palace and Lempuyang Luhur Temple are great for a half day sight-seeing tour. That part of Bali is beeeeeautiful!
I give a vote for Liberty Dive Resort. Wayan, the Balinese owner, is operating a friendly, efficient, clean, and comfortable dive operation. LDR is only about 200 meters walk to the beach entry of the Liberty Wreck, and porters carry your gear.
You can get a massage at the resort. Wayan might be persuaded to bring in a traditional dance show performance in the evening. Do get in touch with Wayan's driver,
Ricky, for transport or a half day tour. He's comes highly recommended by divers for a good reason.
Menjangan has excellent wall diving and corals.
I've heard that both areas have good snorkeling, but I'm not a snorkeler.