Hi John
You'll love Grouse Mountain - if the weather is good the cable car ride up to the top is quite spectacular (but may be filled with sweaty runners who train by running up the mountain daily and then getting the cable car back down before heading off to work!!)
I don't remember seeing the zip wire, (I was there is 2011) but I spent so much time watching Coola and Grinder that I didn't leave much time for anything else. There's plenty to do and see at the top of the mountain but, one word of caution, there are mozzies and knats everywhere up there so take plenty of insect repellent and don't breath in with your mouth open!
As for the Capilano well, I did it but OMG! The sky walk on the cliff side feels much more solid, even if it is less of an achievement!
Have an amazing time - if you have any other questions about the trip, feel free to ask. It still rates as my favourite of all my JY adventures so far.
All the best
Mandy