Garry,
If you get a 400FT mag would be the best! Konvas does take 400ft mags! You can buy very inexpensively one on ebay. This way you will not have to touch the film while respooling at all, which keeps all the dirt out. I've divided film in the past and it turned out to be a mistake. Took me a long time and I did ruin shots due to dust and particles.
Sammy