Hey Susan,
Little Shop of pets is my favorite of the ones I listed!!! I bought my protein skimmer there and some LR. They showed me the equipment room to. It is quite impressive! The place in Nashua is also great. That is where I bought my tank from.
As far as your equipment goes, it's sounds pretty good. I'm not sure about the hang-on wet-dry/skimmer. I thought I read that you could get better equipment if you bought a seperate wet-dry and skimmer. I could be wrong, but that is what I recall. What size bulbs are you talking about, 55watt, 96 watt? In either case, that price of $499 sounds a bit high! Are these all prices from Portsmouth? If they are, I know they are a bit high, but if you want to buy from them because they helped you; that is your choice. I paid about $70 more for my skimmer there than I could have paid online, but they helped so I bought it! Are you buying the light kits with the fixture included? Does your tank have a canopy? You can fit more lights in a canopy, and you can use retrofit Power compact lights, that would save you lots of $$$. You can get retofit 96 watt PC retrofit kit for around $99 shipped to your door with a bulb from many online stores. 4 of those would get you any combination of bulbs you want for about $400. And they would each have their own plug, so you could have dusk/dawn control! LR is definitely a must! Good choice!
I think the sand may be a bit much. The play sand comes in 50lb bags, and the LS comes in 10-20lb bags. That is about 340lbs of sand. I have 150lbs of sand in my 75gl and it is about 3" deep. You can put that much, but that's up to you!
There are many, many, many opinions on lighting, so I would suggest doing a search on here on "lighting". There will be a lot of good info!!!
Hope this helped!!!