I would take both paci's now. As was said earlier by hunterjumper (i think) it will be easier to wean an 8 month old than an older child. Also, I think it would be easier to wean a 2 year old when the 8 month old doesn't have a paci hanging out of his mouth.
Weaning your kids off a paci is sound advice... But be prepared, every kid is different. I took my kid off a paci at about 13 months and she was hell on wheels. The fact that she knew the paci's were there and that she just couldn't have them sometimes was too much for her to understand. That was tantrum after tantrum after tantrum. Not fun.
One day her irresponsible mommy just "lost" her paci's, she was pissed for about 10 minutes and then was fine.
Taking them away entirely was so much easier than weaning I can't even begin to describe it.