Agree with hoops about the sand bed, Sand sifting stars require lots of LS
and they will eat benificial SB critters and in a 46 they will eat the food source quickly. SS snails would be a better option. A fuge IMO
is a great addidtion to any tank and if you have the room should be added. A fuge is different then a W/d and sump.. So your talking about a sump/fuge combo?
Do not skimp on the LR
it will be the main filtration on the tank and is one of the most important parts of a tank. If you must use less LR
then maybe a W/D would be a better way to go.
Do lots of planning and keep asking questions..