Hello Mr. Royale,
Nice rig and dual subs are the way to reality, love it.
Custom McIntosh handles you saw in my photos. There was a message board and McIntosh dealer, Ivan from Massachusetts, making them but has stopped because his machine shop was not consistent.
I have a machine shop that built my glass & aluminum amp racks (to float the amps perfectly over the two REL G2 subs, that can easily do handles.
The only thing I would strongly suggest is to send them the existing side bars. The side bars come off VERY easily, just two recessed screws on each.
My machinst is John Nightingale [email protected] in Virginia.