If you're working on a budget, high lighting isn't necessary if you aren't planning on any high light corals. There are some low light varieties of coral out there that would do fine on regular flourescent lights.
I definitely recommend LR ....but it can be expensive. Look around for a good deal....check out for any sales at your lfs, I managed to find some partially cured LR for about 4.99 a lb...very good price since there was no shipping charges involved. You can find it cheaper online but then you have to figure in for shipping, not to mention that picking it up at the lfs I got to choose my own rocks...and they were very nicely covered with lots of coraline.
For filtration I used an aquaclear HOB and set it up as a refugium. You may be able to find a used one online for alot cheaper than buying brand new...they are an expensive filter. Get a 110/500 aquaclear..they're the largest and have a nice size box for coral rubble, LS and macro. You'll need a small light over the filter if you add macro.
I use my water straight from the tap, but........It's very soft water with a high PH which has worked out very well for me so far. You may want to give your water a try, but test it for anything you can get a test for..hehe..just to see what you have first. I have a 10gallon sitting around that I use as a change water tank. I mix the sw up in that tank after each water change....I just check the SG before I use it and make adjustments as needed. I use "Instant Ocean" and have found that the recommended amount of 1/2 cup per gallon is just right to keep the SG at 1.025.
Here's a site you may find helpful.....I did....
http://www.reefkeeping.com/issues/2004-05/rhf/index.php
Also, here's some directions on setting up a diy refugium if you choose to go that route for filtration
http://www.wetwebmedia.com/hagenrefugart.htm
I havn't found sw to be any more difficult or time consuming than a fw tank....actually easier than my planted communities. But, I keep on top of weekly water changes and regular maintenance...my tank is a 20long BTW....
As far as inverts, many types of snails...nassarious are great for sand sifting and turbo snails and hermit crabs for hair algae...actually, check out the stickies in the marine section here...those in the newbie thread specifically. I found them to be very helpful. There is a guide there for cleanup crews. Try this page out for some brief info on critters
http://www.nano-reef.com/articles/?article=5
Hope this helps some.....make sure you do your research as far as fish and what types would do well in your tank while you're waiting for the tank to settle in. A QT tank is a great idea BTW.....I would set one up at the same time you setup the main tank. Don't put any LR in the QT though, because if you have to treat for anything..any meds you use will kill off your rock. A sponge filter should do for that. If you get the Q
(A frienly warning :Buy the biggest tank you can afford. Get propper lighting: T5 should do, not as expensive as Halides. Run a sump and a skimmer, this way youshouldnt have any configuration problems later on.) 