Derek,
There is a design by Michael Chua that looks interesting to me. It’s a coax based on the Eminence Beta 10CX. An interesting driver that you screw a one inch compression driver into the pole piece. You can use any one inch CD that has that thread pattern. Michael chose a Selenium
220. The enclosure is a simple, 1 cubic foot box and I believe the Beta is surface mounted, which would not require routing precise rebates. It looks like it comes in around 94 dB, so plenty sensitive. This might be a good design for small rooms and it can be built fairly inexpensively ( around 270.00 for the drivers plus your cabinet material and Xover parts). You can find the details on the Ampslab site. Michael is very helpful and responds quickly to email.
Jamie