I have a potential bride to be client that is lactose intolerant.  I've not made a lactose free cake before and was wondering, how will the texture, taste, and durability of the cake change if I substitute lactose free milk, lactose free sour cream, and lactose free butter for the "real" stuff?   I would appreciate any help and suggestions.

You can use almond or rice milk. I do all the time as my son is lactose intolerant. Doesn't change a thing in taste or texture. I also use lactose free sour cream if I want a pound cake., and substitute oil for the butter.

Thank you jchuck!  Do you use a butter extract to add back the butter flavor since there is none in the oil?

I have use lactose free milk in my cakes, and it honestly doesn't change the texture at all. As for the other ingredients, I'm not sure since I've never used them.

No Vanessa7  I don't add butter flavour, I just add whatever extract/flavour suits the cake I'm making at the time. I just bake my cake as per normal but use lactose free ingredients. Comes out tasting the same as cakes regular cake.