Winexpert is the one manufacturer that uses a number of different yeasts in their kits. Personally I would not substitute yeast in a WE kit. UNLESS, I was going to a liquid yeast, like Wyeast.
If you do want to try a different yeast, get an identical kit, and substitute in that one. Then you will be able to see the difference for yourself. Don't forget to age for a year before deciding.
It is not necessary to make a yeast starter for a wine kit. Believe me, having run a Ferment on Premises, I've made thousands. However, the back of the EC-1118 package gives you basic instructions. Yes you can make a better starter (nutrient, etc), but I've never done it.