I am in the middle of building the HWK with 4 15's and just to compare I want to build the WO with two maybe 4 15's. Anyways I was doing a search and the most information I found about adjusting the WO to work with 15's is to increase the height by 2inches and angle the baffle? Is there more to it than that?

Yup,
I have only heard of one person having any luck going bigger than 12" subs in the WO. I have helped a couple people design them larger and the results have been really dissapointing. I have heard one person use 15s succesfully and he used a pretty shallow driver. That was the only time I have seen the height increased and the other dimensions left alone. All attempts to widen the box to accept deeper woofers have failed (to my knowledge at least)

THe HWK should be a monster. I would say stick with it.

Take care,
Robert

Adjusting the shape of a normal size wo- say 36 x 36 to accomadate your driver would work fine.  Although it would be a hell of a wood working project, changing the shape of the compression and sealed chamber, yet keep their volume and the horn path the same would be the best bet.

The problem with scaling the entire design is that you loose alot of its benefits (size- dual folded horn in 3 x 3feet!!! -Not anymore)  and change the geometry of the horn.  Granted all the ratios stay the same by definition of scaling- the added area of the throat and volume of compression chamber would no doubt lead to the WO sounding bloated and slow.  No longer would it be a beast of speed and power- say a Bently- it would become a Semi Truck.  Great for low end and SPL, but horrible for negotiating turns in style like its 10" 3 x 3foot predecessor.