You're quite welcome, Jessica. You won't need a jacket or fleece, that's for sure. If you visit some of the waterfalls on Babeldaob, you may consider bringing one of those cheap rain ponchos, but it's hot this time of year and the seas are calm. I think you meant Neco Marine, also a good outfit I hear, but never dove with them.
If you want to see mandarinfish, dive Cathedral Cave in the late afternoon, and then hang around the front of the cave between 5 and 6 p.m., preferably right after the full moon. They're hanging out in the "leaf litter" coral. That's what it looks like -- just a yard full of dead leaves in the fall, but it's all individual pieces of hard coral.
Oh, and one piece of advice that I had passed on to me that I try to pass on to anyone going to Palau for the first time. WATCH OUT FOR DOWNCURRENTS. During the peak of tide changes, water spills over the reef and creates some nasty downcurrents that can transport you downward 20-30 feet in a matter of seconds. This happened to a friend of mine and the only way she got out of it was to hug the reef (I know, you're not supposed to touch the coral, but when you're in trouble you have to make tough choices), fully inflate her BCD, and crawl up the reef. Inflating the BCD may cause problems later on when you reach shallower depths and you'll shoot up, so don't necessarily do this unless absolutely necessary and you are prepared to release air from your BCD on the ascent.
When it happened to me, I was doing a blue water safety spot well away from the reef, and all of a sudden I felt my ears popping. I checked my depth gauge and I was at 45' already in the space of several seconds. Luckily my current wasn't that strong so I was able to kick up and do my safety stop again, this time watching my depth gauge the whole time. I hope I didn't scare you, but I also hope that at least you're aware of what to expect if something like this happens to you wherever you dive.
Dive safe.