Your lighting plan is more than adequate to keep macro algae. I have just 2X55W over my 26 Bow and harvest algae at least once a week. I also have Xenia, mushrooms, zoas and other button type polyps in there. For what it's worth, I have caulerpas growing under simple CF lightbulbs I bought at Home Depot.
The pink sand is a nice idea.. yeah it is expensive. It's hard to find because, well.. there just aren't a lot of pink sand beaches..or at least as many as the white sand beaches. Pink sand is pretty interesting. Unless it is "treated" to make it pink, it's a result of the calcium/shells of dead Forams. You may even have some of these neat lil' creatures in your tank. They are quite common on Tonga Branch. Here's some more info on Foraminifera: [ame]http://en.wikipedia.org/wiki/Foraminifera[/ame]
I use a Mag7 as a return from a 5 gallon DIY acrylic sump on my 26 Bow. It's not too much flow at all. I point the returns in a way that they chop the water surface and stir the oils and such towards the overflow. I'm just about ready to tie "Sumpzilla" back into my system and to push the water back from the basement to the display upstairs, I bought a Mag18
The 75G is almost cycled now. Ammonia 0 Ph 8.3 Nitrites 0 Nitrates 10 There is still a small pile of "goo" from the decomposing piece of shrimp. Yuck. I don't dare pull it out (stinky!!!)
I have copepods and amphipods in the tank!! I hope to have the macros planted in there by next week. I will only be adding 1 or 2 kinds of macro to the tank at a time. I want to give them time to adjust so they don't go sexual. It seems everytime I add larger amounts all at once, it all dies off. The first two will be the red dragons tongue and the prolifera. Next will be the red and yellow graceleria (spelled that wrong I'm sure). Then I will add the green and red feather. Last will be the blues / purples. If there is any room left after that I will add some of the razor caulerpa and red kelp.
In about 6 months or so I will add the seagrasses. I will have to wait and see how it goes till then.