Zihuatcat --
the Mushroom Forest is a drift dive. Captain Goodlife takes you out in his skiff and drops you at a spot that will take you 50 minutes or so to reach the take out point. Ideally, take out will be against the southern headlands of the St. Cruz bay, in front of the "Blue Room" submerged cave. The Blue Room was hard to locate from our vantage point of water level, so you might ask Capt.GL to motor over to it and catch it on a second dive.
As for contacting Capt. GL, I can only relate that the dive shop in Lagun told us of his water taxi service, you might contact them for a cell phone number. I know he has a cell but not sure how much advertising he does, or whether he shows up in any of the usual tourist service blogs/websites. He is a bit unortodox in all regards, if that hasn't already become obvious. He was a good waterman and his food was good, I have no reservations about recommending his service.
As for lodging, the All West Apartments are well situated overlooking the cove at Westpunt and seemed a reasonable if plain place to stay. They are very popular and book well in advance so don't wait too long if you are planning a high season visit. They also have some apartments further into Westpunt, not so close to the water, which looked comfortable.
We stayed at Marazul which is a bit more upscale cluster of condo/townhouse type units. They do have a nice pool area and a convenient source of tanks is located in a dive shop next door. I would be a little cautious about rentals in Marazul as last spring they seemed to be undergoing a transition from a property manager operated "dive resort" to "for rent by owner" operation. Our unit was less than advertised re: some little things like no hot water, no screens on some windows, postage stamp view of ocean. We paid $85/night for a 10 day visit.
Wherever you decide to stay, be sure to ask about window screens. Curacao, being fairly mountainous seems to wring more moisture out of the trade winds and rain means mosquitos. (and possibly dengue fever)
Another location to consider for lodging and dive operations is Lagun, about 20 minutes south of Westpunt. I found a ocean front/view apartment there for $100/day, considerably less for mountain view. A good source of lodging options of Curacao or any of the ABC islands is VRBO.com if you are not familiar with them (Vacation Rentals By Owner).
Good luck on your adventure.
Rod