I've had these aluminum Excel rims bookmarked:
Buchanan's said they're not something they were able to find in their Excel catalogs to order, so you'd have to track down the Excel part number to see if they can get them, or you can buy from Webike and have them shipped to their shop.
In Thailand those rims are available on assembled wheels using OEM hubs and a BARTubeless setup, and that is the option that appeals to me the most. I've been emailing BARTubeless back and forth about ordering and might finally be in contact with someone who can get them ordered for shipping to the USA. Will start a thread for it if that happens, though if anyone else is seriously interested in that I recommend reaching out to stefanobassi [at] bartubeless.it directly as it's a low priority for me at the moment.

SP TAKEGAWA : Aluminum Wide Wheel Rim Kit [06-09-0020]
Product Description: SP TAKEGAWA Aluminum Wide Wheel Rim Kit [06-09-0020] : Fits:HONDA CT125 JA65-1000001- : HONDA CT125 (JA55-1000001-):... - Webike
japan.webike.net
In Thailand those rims are available on assembled wheels using OEM hubs and a BARTubeless setup, and that is the option that appeals to me the most. I've been emailing BARTubeless back and forth about ordering and might finally be in contact with someone who can get them ordered for shipping to the USA. Will start a thread for it if that happens, though if anyone else is seriously interested in that I recommend reaching out to stefanobassi [at] bartubeless.it directly as it's a low priority for me at the moment.