I agree with above. Just because you are going with a
FO tank doesn't really change the rules. A 100-150 lbs of
LR plus a good skimmer will make life a lot easier on your fish and render a wet/dry moot unless you intend on seriously over-stocking. I'd also advise some type of sump on a 150gal simply because it makes maintenence and skimming a lot more efficient and centralized. The biggest problem I've encountered with large tanks is not enough circulation, but efficient circulation. Plan your plumbing and filtration using common sense. Such as, water being removed form the tank on one end, and being returned on the other, and top-down water circulation vs horizontal firing power-heads. On a 20, 30, or even 55gal, this isn't as big a problem. When you start getting up to 150gal you need to think things through.
On the other hand, if you don't have the option of using a lot of
LR (cost, size, short term set-up, politics, etc) you'll need some help with the nitrogen cycle. In that case, I still say 'bah-humbug' to wet/drys because those good old Emperor filters with the bio-wheels do the same darn thing in a lot smaller package with less screwin' around. You can then pull the wheels off at a later date if you decide to add
LR to the tank.
If the tank is going to be heavily stocked, a large cannister filter with
AC would certainly help since without the typical assortment of filter feeders and invertebrates running around you'll have more suspended organics in the water too big for the skimmer and too small for the fish tp grab.