I am wondering if anyone knows how to make an Edelweiss and a Trumpet Gentian. I am going to be making a Swiss cake, and these are pretty much the national flowers. Any suggestions will be appreciated.

So very sorry nobody has been able to help you. I really can't either
Have you tried a google search? Find some good pix of each flower and try to copy them? That 's what I;d try.
Founds this info:
http://images.search.yahoo.com/search/images?_adv_prop=image&fr=yfp-t-701&va=Trumpet+Gentian
scroll down a bit and PME has a cutter for the gentain
http://images.search.yahoo.com/search/images;_ylt=Ajml8yLrwD3dHD9op1zb63ibvZx4?fr=yfp-t-701-s&toggle=1&cop=mss&ei=UTF-8&p=edelweiss

someone suggested to me going to a florist and asking for just 1 of the flowers so you can see it and copy it from all angles. (of garden centre if a florist wouldn't have the plant)

On lovely tutorials, there are lots of flower tutorials. Although they don't have the particular flowers that you are looking for, there are some similar ones. You may be able to figure out how to do these after viewing them.

Personally if you cant find a tutorial the next best thing in my opinion would try to get two at a florist, dissect one of them and use the second for copying. Wish you the best