It would be much simpler for you in the long run to do the new system. The familiarity of how it goes for counting is about the same - just different values and overall ranges, which is probably the easy part to change! All the new recipes, books, prepared meals at the grocery store are all in the new points values, and in my opinion, in the long run it will be much easier to just go with the new plan.
We're fat chicks, not doctors. Please see your physician before taking advice found on the internet.