You'll add those things when you check out from Picaboo - they cannot be added to your Groupon, as these offers are for set values.
I'm sorry but I'm not entirely sure what you mean by "the standard order" in your second question. If you purchase the voucher for two books, you can keep one for yourself and give the second to someone as a gift. In that case, you can order two completely unique books with your voucher. Alternately, if you want to give a Groupon as a gift, that Groupon must be redeemed under a separate Picaboo account- you will not be able to redeem both under your Picaboo account and give books purchased with that voucher as a gift. As noted in the fine print, this offer has a hard limit of one per person.
Hope this helps!
Nov 20, 2012