Lactose -vs- Splenda, sweet cider

I'm getting ready to make a batch of Sweet Raspberry Apple Cider (4 gal), the recipe calls for 1/2 lb of lactose at bottling, however lactose is kind of hard to find around here. I do happen to have a bag of Splenda, so my questions are;

How much Splenda would equal 1/2 lb of lactose?

What would be the difference in the flavor, substituting Splenda for Lactose?

Thanks in advance!

EDIT----
also, has anyone used the LorAnn Oil candy flavors LorAnn Oils to flavor ciders? how did that work out?

Splenda will not give the cider any mouthfeel. It's about twice as sweet as lactose to most people.

I also just found out it doesn't dissolve as easily as cane sugar, or lactose...
I just bottled a 6 gal batch of Johnny Jump up hard cider, and I sweetened it with about a third pound of lactose (I found it at a health food store!) and three cups splenda. I dissolved both (or thought I did) in 2 cups of boiled & cooled (still warm) water.
Well, when I was done bottling I found about a cup of undissolved splenda in the bottom of the bottling bucket.

I guess I got in too big of a hurry.

From what you said about how sweet it is, that might be a good thing...