How to set up a temporary POS system for a trade show?

[SummerSun]

I have been using Shopify on my desktop for our online store for a while now, but we have a really busy trade show coming up and I need to set up a POS system for those two days and I'm so confused. I don't need all the bells and whistles as this is a two day only thing - I'm going to hire what I need. I use Android normally, but after reading reviews, I'm going to go with iPads for the trade show.

Can someone please confirm if this is what I would need to run two payment stations. 2 x iPad's and stands, 2 x card machines, 1 Shopify POS (light) that would run both iPads and link up with my usual Shopify system. Can I have a third iPad out the back for trouble shooting, or do all iPads have to be linked to a card machine? If not, what is the option for trouble shooting when both iPads will often be in use for customers purchasing? (Is there even an option for this?)

Is there anything else I need to think about for a trade show? I'm new to this but the previous business owner said this show is his busiest days of the year, so I want to be prepared. 

Thanks in advance for your help! 

[Retail-King]

Hey SummerSun, 

The card readers are a 1:1 relationship with the iPad and I would not recommend switching them between two iPads as it can cause misconnection issues. You are good to use the POS Lite and run a pretty simple set up but you will want each iPad to have a card reader unless you will be doing lots of cash sales. 

Let me know if you have any questions and I am more than happy to help out!