All credit to you for your build, simply wonderful.
Mine will be quite standard looking, though the Curly Birch has a gorgeous pinky hue, with a swirly pattern. See here
For ports, I'm following some input from the guy who I'm building the speakers for. He's of the view that the larger ports ably suit the cabinet volume and driver specs. Note, the ports are adjustable....and he can always close one off should that be required.
Robin, contact Yates for costs...but the very large piece of 25mm ply comes in 3050mm x 1200mm sizing. Depending on veneer, I think the prices were approx $600/piece. I shaved a few mm off the cabinet design to get all 12 panels out of one sheet....very lucky.
The owner then sourced some solid hardwood Oak panels for the front baffle. I then laid these up using biscuit joins...will sand, then fit over the 'pre' 25mm ply baffle you already see in the pics. So, overall baffle thickness is 45mm.
Fantastic funky amp cloth will be used for the grill frames, along with upmarket spikes.
The drivers have been rewired with solid silver, but we've retained the attenuation for now....may remove depending on owner's room, etc.
New heavy rubber underlay used on three opposing walls. I chose this to maximise volume of the cabinet. The rubber is only about 12mm thick. (Funny that the underlay is called Gold...perhaps the owner should buy some Monitor Golds instead....?)