If you are thinking of flat water sailing the sup, you will be disappointed in the performance. Even for beginners, it wont stay up wind. So not really worth the effort.
If you are thinking to sup sail small surf, I couldn't encourage you more. Its great fun.
BUT in the surf, you need a really strong connection.
So I think you need to either formally put in an insert, or source an old sup with the insert.
The old silver range of starboard mostly had windsurf screw in inserts.
Many of the sunova boards had small slots.
The windsurfer LT isn't too bad,
Many other older options, Bic Jungle, Mistral Pacifico.
Unfortunately most windsurfers are not good in sup surf conditions, (either too small for sup surf conditions or way too little nose rocker)
One exception is the Kona which is really good. Strong mast connection, duck tail works like tail rocker, and enough nose rocker.
I like the Kona more than the LT in small surf, and the straps help going out at speed. But the LT is pretty good. Kona's are rare in Ausralia.

the little black marks in the middle are screw in inserts