I love your colors… and I think the flowers would be gorgeous.
What sort of a look are you going for? You could do so many things- and I do think the idea of an arragement surrounded by candles is absolutely wonderful.
In addition to the roses and peonies you may want to consider garden roses. They are incredibly romantic and compliment peonies very nicely:
Immediatley when I looked at your colors- the brach idea entered my head.
My idea for this it to find a canister for a base (possibly a tin coffee can) fill it with plaster and place the branches in it and let dry. After the plaster is dried and the branches are secure- visit a fabric store and pick up some fabric in your wedding colors. Use the fabric to cover the can the branches have been placed in. Then, depending on your taste- you can decorate the braches.
You could hang some votives in the trees http://www.flowersandsupplies.com/Votive-Tea-Light-Holders_c_5-2-0.html – this website has hanging test tubes- you could inserrt a flower step in- or something else creative. I’ve seen the branches with crystals http://www.etherealdecor.com/crystal_wedding_tree_manzanita_branches.html or some brides buy small green floral balls- cover them with flowers and hang them in the branches. Another idea would be to place floral balls (with flowers in them) around the base of the braches.
If you don’t like that idea- you could always do an arrangment- I couldn’t find any in your colors, but you could tweak these to fit your theme- When you few these be sure to hit the additional pictures button.
I like the above link, because it would be chic to do multiple vases full of one type of flower- but different flowers. I think it would also be cool if you grouped your votives candles in groups of 3 instead of just a single candle
http://www.bbjlinen.com/Site/gallery.cfm?galid=1&galsubid=1&phgid=384&ViewAllCat=0 This is sort of the branch idea- but the branches are a little more qwispy and are hanging in votives. To incorporate the pink you could lay a rose bloom on every guests napkin. I think it’s a really great person touch and makes the tables look amazing.
http://www.bbjlinen.com/Site/gallery.cfm?galid=1&galsubid=1&phgid=301&ViewAllCat=0 This is really simple- and really great. A simple rose centerpiece. It’s timeless- and some grouped votives would realy make the table glow.
http://www.bbjlinen.com/Site/gallery.cfm?galid=1&galsubid=2&phgid=403&ViewAllCat=0 I love the look of long tables. The vases with colored water and floating votives on this table are really gorgeous. With your colors, I would probably just use clear water- it would still be lovely.
I hope this helps