I converted my 29 gal FW tank to a SW several months ago... and I've had pretty good results.
As far as the LR goes, the general rule of thumb is 1 - 1 1/2 lbs. per gallon of water. For the LS, I guess that depends on whether or not you're going to do a DSB or not. There is a formula based on the dimensions of your tank. I have 30# in mine and it's about 2-3" deep (just to give you a general idea).
Most people would recommend using a skimmer. I went skimmerless up until today
. I'm just starting corals; it's not as critical with a FO system. Most reefers use skimmers, but many people have great aquariums without one. Do some searches on here and you'll find more information.
Lighting is another ball of wax. There is a basic watts-per-gallon formula that you can use, but many more experienced reefers will argue that it doesn't make sense. Your lighting will depend on how DEEP your tank is and what kinds of corals you're planning on keeping.
If you post the dimensions of your tank, along with what you want to keep, I'm sure someone will be able to help you with more specific information on the lighting and sand.
HTH
~D~