I still really don't know what you mean, but if you are going to add a version number to a thread, you will have to do some custom coding...you will need to add the input element to the "newthread" template, write a plugin to take action based on the value in that field, and alter your database to store this version number. Then you will have to alter your threadbit templates to display this new field.
I want find something that but this plugin in premium version is very expensive. With 50$ in previous days i can buy the vBulletin 5. Very very expensive this product.
Anyway, I do not know another ready made plugin. If you want something else, you'll have to have it coded for you, which probably won't be any cheaper.