I'm making my nieces wedding cake (5-tier with bottom being 16"r) What kind of cake stand do you suggest? Or should I even have one and just have it on the cake board on the table?

I wouldn't even worry about a cake stand with a 5-tier wedding cake. If you don't already have a stand that's 16" big, they are very expennsive. You could always double up on the boards that the cake is on to give it some height and wrap the edge in ribbon.

you need a wood round, or something heavy duty.

These come in several sizes and are very reasonably priced. I have 2 different sizes and they're very sturdy and look nice with almost any decor. I insist on having a cake stand with feet so that I can get my fingers under it for easy moving and positioning!

http://www.globalsugarart.com/product.php?id=27224&name=Cake%20Serving%20Stand%2018%20inch%20Round%20by%20CK%20Products

Where I am at, the brides can rent them from a rental company that does their tables and chairs....All the rental companies around here have them. I do not carry them because of space issues, and they are stinking expensive! I usually have to remind the brides that the stand is an option, and to contact their rental agency!