If you don't feel like driving the 3-4 (depending on ceremonies/traffic etc) hrs from DPS to Tulamben, then just dive in Padang Bai (1.5-2.5 hrs) or stay around Sanur (25-45 mins). Both places can reach Nusa Penida/Lembongan by boat (for coral, mola mola, manta rays). Padang Bai is pleasant and there are now excellent resorts in the Manggis area, just a few miles from Padang Bai. Sanur is "central" and there are great hotels/villas there as well. Ubud/Jimbaran is 50 mins from Sanur and a great way to spend the last day before jumping on the plane.
In Padang Bai/Sanur, you'll be limited to 3 day dives by boat in Penida/Lembongan/Gilis. You can do a nightdive in Sanur Bay. Same in Padang Bai. If you want shore diving, the resorts in Manggis have coral heads and the like, but only as an excuse to get wet and nothing very interesting.
Tulamben/Amed has the better shore diving for muck. I suggest staying at Scuba Seraya, which is very popular with photographers. Diving the wreck from a boat is my favorite way to do it, no need to deal with the rocks (and waves on bad days) with gear and camera. I can squeeze 6x90mins dives a day at Seraya if I wanted to. You just have to deal with a long drive there and back.
If you've never been to Bali, I'd personally not do Tulamben for such a short trip, but just hit Penida/Lembongan and hit the tourist traps like Ubud/Water Gardens or Jimbaran/Ulu Watu or Tanah Lot as well. You'll be back from the diving by 3 or 4, then head out to the different places by car (you can easily hire one, just PM me for driver contact) and enjoy some nice restaurants, probably some of the best value in South East Asia (except for alcohol because of the local tax... BUY YOUR ALLOTMENT AT THE DFS before arriving in Indo!)
I've been using Indonesian owned and run BIDP exclusively for the last 13 years for all my local diving in Bali. Have fun!