We are currently interested in buying pneumatics. What is the best (and cheapest) way to buy them? I see that the Vex kits include custom Vex mounting brackets. Where would you get these if you buy from a different place? Also, I compared prices on the SMC website to the prices on the Vex website and the prices seemed to be about the same. Are there any other places to buy them from?
Also, how long does it take a pneumatic to fire once the digital output is turned on?
I highly recommend checking out PLC Center. You can use the SKUs from the part kits from VEX with the PLC Center catalog, like you did with the SMC website. Most of us here on the forums (including myself) have made purchases from PLC Center and I’ve never heard unfavorable reviews of it. There is no way to purchase the mounting hardware because it’s custom made for VEX. There are ways to make equivalent parts using standard VEX metal, though.
I would recommend figuring out what you need and the comparing prices from VEX and from PLC Center. Just make sure you know to expect several week shipping from PLC Center (not 2-day shipping from Amazon ;)).
As far as a delay on the digital out firing (ignoring pressure), there is definitely a slight delay (the nature of electronics); however, the delay is in milliseconds if not shorter and shouldn’t be a problem unless your doing something very technical.
For starting out and buying the whole kit the vex Kits are usually a good deal. Just know that if you buy form plc that you do not get the driver cables they have to be purchased from vex. The brackets are not that important in my experience. We usually don’t use them even though we have them.
Thank you for the responses, I will look in to the prices of PLC compared to Vex.
Here is a pneumatic chart I made up.
The SMC Part number you would just type into the http://www.plccenter.com/ search toolbar and it will come up or be the first on the list. I included the price of each, the full name, and the short name of the product.
This has helped me a lot, and hopefully it helps you 
VEX Pneumatics Chart.pdf (339 KB)
I was just making one of those. It saved me from going and finding them myself.
On the PLC center website I see prices for New and Surplus. Surplus is cheaper, which did you buy?
I have not been able to find the “Tire Pump Fitting - Shraeder Valve With 4mm Tube Fittings” on the SMC website of PLC center. Where did you find it?
PLC and SMC does not sell the Shraeder Valve. You have to purchase it here: McMaster-Carr
This is the model number you want to purchase: 8063K31
And personally, I have not purchased any pneumatics 