Inca, congratulations! I think this is a very sweet idea and you can count on me to send you some white beads to join the party in your necklace. I can't believe they're still holding up your fiance's papers and will certainly add this concern to my prayers for you.
I know of a couple of people who might be able to make you a lampwork heart and have put in some links here...
http://shop.ebay.com/merchant/croweyecreations this is Vicky, or Victoria Burby. She lives in Bangor, Maine and I have a number of her bead sets and have seen lots of her work in person. She does a beautiful job. She doesn't have any heart beads on her website but I've seen her make them before and have no doubt she can make you one.
http://www.mindexcite.com/croweye/ This is her website in addition to her ebay listings.
http://stores.shop.ebay.com/Sunrise-Beads-and-Sunrise-Frit_Mixed-Sets-Beads_W0QQ_fsubZ2QQ_sidZ62269653QQ_trksidZp4634Q2ec0Q2em14?_pgn=1 These people are also in Maine, north of Bangor. They make a series of beautiful heart beads that don't have the hole going horizontally but I think they might make one in whites with a horizontal hole if you ask for it. I've seen some of their beads, they do a good job too, they have a distinctive style. I don't know these people personally like I do Vicky.
http://www.sunrisebeads.com/catalog/index.php?main_page=index&cPath=9&zenid=97ec3126b8bda77e366a8965676083f5 This is their website with the first page of hearts.
If those two don't have anything you'd like there is another beadmaker I can recommend: http://stores.shop.ebay.com/River-Oak-Acres-Lampwork-Beads__W0QQ_armrsZ1 and here's the off ebay store: http://www.riveroakacres.com/ I have beads he made too and they're beautiful.
Good luck with this Inca! 
Pam
It is only with the heart that one can see rightly, what is essential is invisible to the eye.
Antoine de Saint-Exupery