Hi and congratulations!

We did the same thing for my son's wedding!

One question....when and where is the reception? If it is in the summer...you will want to make sure that the hall is air conditioned WHEN you set up....not the next day. They will be fine if they are in an air-conditioned room all night. OR, on the flip side....is it a winter wedding? Again, you don't want the hall TOO HOT for the whole night. Make sure the heat is turned way down. So...if the temperature in the room is OK for the whole night, you should be fine. Ours were lovely!

Here is the wholesaler we used. They were excellent and there are many choices of EACH color! The flowers arrived right on time and there were no problems!
http://www.rosesource.com/

Another one is this wholesaler:
http://www.growersbox.com/

Good luck!

PS--I forgot the mention. Follow their instructions to the letter!!
We had a Saturday wedding, so the roses arrived on Thursday. On Friday, my sister and I did them up. One warning.....it takes a lot of work to unwrap, cut the stems, put them in water filled with rose preservative, etc., so allow lots of time to do this. Again, I have an air conditioned house...so it worked out good...they were in the basement (very cool) overnight. You CAN'T use standard refrigerators. (They will tell you that). Florist refrigerators are different. But, in the end, IT'S WORTH IT because you will have saved TONS of money.