I just returned from a 3 week trip in Bali (amy - June) and made several dives...I stayed in Amed at Amed Cafe Hotel. Its nice, clean, with a/c and pool. It is not bungalow style, so you will not get bitten by misquitos at night as they have glass, as opposed to wooden windows. Its in the "main" part of Amed, which is very spread out. I recommend staying in Amed as its only 20 min away from Tumbulan and you should get to the wreck early before everyone else so you can enjoy it. It is not resort like high scale, but still nice, esp on the budget. Ask for discount, as with all places in Bali, and most times they will give one...as tourism is down.
I dove with Eco Dive in Tumbulan with a DM named "Okta". I had no problems and I enjoyed diving with him as he was able to find most of the things I wanted to photograph, including a sea horse. He was enjoyable to dive with. The entry and exit at the Liberty is a bit rough as there are rocks there and waves, however Okta has cousins there who were able to help me (I had severely injured my knee the day before, so it was a little hard to walk).
I do not know ur diving level, so you may want to check out the level of the DM more than I did. But overall, I had a good experience there. I agree with the other posts who recommend having your own equipment. At least when I brought mine, I know how it works, I know it works, etc.
I enjoyed all my dives at Tumbulan. The fish are friendly sometimes to the extent I was afraid the surgeon fish were going to hit my head with their barbs.
Again...make sure you arrive early, and enjoy your trip!