Too many choices (help a FR newbie)

I've had a pair of WR125S for some time now, and finally got around to doing something with them.
I mounted them in some temp. cabinets, and was quite impressed.

I am not new to speaker building, but new to FR.
I haven't built much in the last 20yrs, and I'm not as technically savvy as most on here, but find this FR thing to be quite interesting (and maybe a nice break from building crossovers).
I guess my problem is that I'd like to start a project with these, but there seems to be so many good, and different possibilities, I don't know what to do, or where to start.

Should I just begin with a simple ported enclosure, or do something a little more complicated?
My woodworking skills are fairly good.
They'll be in a room roughly 12' x 20' with 8' ceilings, connected to a Marchand PM22 amp.
I don't currently have one, but can build a subwoofer, if need be.

One more thing.
Can somebody explain this chang thing to me ?
It's a horn variation loosely known as a big-vent-reflex. (Bit of a misnomer in a way, given that all chambered back-loaded horns are big vent reflex cabinets). Basically, it's a specially designed bass-reflex or MLTL cabinet, but rather than using a regular slot vent or port tube, it uses one or two waveguides instead.

In your case I'd be inclined to go with a miniOnken & support with dedicated bass drivers.