Hopefully you're posting this well ahead of your wedding because you're going to have a big of legwork to do in order to get all the materials you need. For the orchids, go see your favourite florist and see if they can order in the blue orchids for you. Take the picture with you so they can see that you are looking for a rich colour saturation, not just a hint of blue. They should be able to get you the number of stems that you need without a problem. As for the vases, try a dollar shoppe or a place like Michaels, who carries a lot of wedding related items. They would also have the mirror tiles available but as a last resort go to a place that cuts mirrors and they would do a custom order for you. But, before that,check a a shoppe that sells kitchen/bathroom tiles or wallpaper and see if they have mirror tiles. I think you would want them to be 12" x 12. The beaded ribbon would be available at Michaels or a fabric shoppe. Now as for the blue napkin, you could use the paper napkins from a party shoppe, but you want a good sized dinner napkin, not a small napkin like you get for birthday parties. You might have to special order these, but before that, check to see if you can rent them from a place that rents out table linens. That would likely be less expensive than having them made for you.
Once you have all the items, do a test run on one table setting just to see how long it takes you to put it together. I would do this at least a month ahead of the wedding just to see how long it stays fresh and to see if the orchid bleeding into the water is actually a problem. My guess is that if you are getting married on a Saturday, you should be able to do the flowers on the Thursday without any problem as long as the orchids are really fresh. When you get them, the orchid blooms should not look papery nor should the buds. The colour should be bright not faded.
Putting the beaded ribbon on the vases could be done as soon as you have the vases. Once the glue has dried, carefully put the vases back in the storage box that you are using. Have everything boxed and labelled and set in a place that you won't forget about. If you are using the fabric napkins, make sure they are ironed ahead of the wedding so they are ready to be placed on the tables. Hopefully, you have a maid of honour and bridesmaids or other friends who can help set these up at the reception venue for you. On the wedding day, you should be doing other things like getting your hair done and having your make-up put on.
I am a retired florist with 25 years experience and have done many weddings over the years. If you need any other information or suggestions, contact me through Yahoo Answers and I would be pleased to help you if possible. Best Wishes and I hope you have the wedding of your dreams. :)