You have to give people time to respond, 1 1/2 hours is not a very long time to wait!

That was helpful advice, so no need to slander what is possibly a decent forum. The reason why they told you this is because its (FO) isgenerally considered an old, out dated, and in-superior style.

LR is the best filter you can have in an aquarium, but:
FO can be accomplished, but IMO your best to set-up a sump. You need a decent sized, decent quality skimmer, not a hang on back or airlift either, here
is SkiFletch's recomendations, which I thouroughly agree with..
Research DSB's, otherwise known as Deep Sand Beds, arguing about their usefulness is like talking about religion, LOL. People have strong opinions about their use in SW aquaria, so your best to come to your own conclusion. They can be a great filtration method for heavuily stocked tanks, and can be incorporated into a sump.
Other filtration could be accomplished via some decent quality external canisters. Media could include carbon, sponge, LR rubble, noodles, filter wool, etc.
The best advice I could give you, if your serious about creating a FO, is to join a local reef/marine society, and seed your sand bed with samples taken from others sand beds, just ask them to scoop out some at a meeting and so forth. This seeds your sand bed with maximum life, from various sources.
What is the size of the tank, and what water turnover is your internal pump rated for? Also, what do you plan to keep in it?