hwrcwby81,
I've built at least one kit from each of the companies you mentioned. As far as I'm concerned, 'Model Slipway' is the best. Not that there's anything wrong with the others, they just are not the same 'quality'. If you've got some experience, and if you know the sharp end from the handle end, I doubt if you will have any huge problems with any of those company's kits.
Have fun.
- 'Doc