Many thanks to all of you who gave me feedback on this topic about a week ago. You saved me a lot of grief!
After borrowing about 15 books from my local library that dealt with the topic, and after confering with the bride-to-be, we opted for a Champagne Jelly that we will make.
The cute little rosebuds will be used to decorate the jars, along with a nice lacy white fabric and some ribbon. I am sure that it will look great and the recipe is very simple to make (5 ingredients, about 15 minutes of work).
Now, I have a question: can you, say, quadruple a jelly recipe or is it better to just make a single recipe over and over again? Any "jellifying" issues, i.e. the jelly not setting, etc.?