4K/8K Norton is all you need for the time being, after the 8K go to the leather strop if you do not have a pasted strop. Jury is still out whether or not you need the linen.
If the back side of the leather strop is very smooth you could put paste on it however if you want to use pastes you better get yourself a bench strop. As no haning leather strop is perfectly flat you may get uneven wear when you use it with pastes.