Splenda is the best artifical sugar substitute. You can use it measure for measure and it works great. No bad taste. If you just follow the recipe, you will be fine.

Stevia is my favourite. It is natural. Just be cautious as there will be a bitter taste if you use too much. A tiny bit goes a long, long way.
And don't buy that stupid stevia mixed with fillers. Get the pure powder, not the kind in little envelopes. Why they add junk to a good thing is beyond me.

This is a great lifestyle. After a while, you can't imagine eating the old way. It doesn't appeal at all. You'll get lots of helpful tricks from this forum.

Enjoy the cheesecake and all the best.