You may be able to change intake to the rubber boot type and use the common VM22. It's a simple style of intake and there are various configurations available new, but I can't name you one right off my head, I'd have to search the internet too.
There's all kinds of stuff out there, but it'll make the price higher. If you have to run a Mikuni and can't find the flange styles in stock.
I went with a cheap Chinese carb, but the jetting was way off, so I spent an additional $15 for jets, after I done some main jet resizing with tiny drill bits to get it in the ballpark.
The story of three wheels and a man...