Since the Arduino boards are open source the clones are generally just as good. The main advantage of buying the official boards is higher quality control, but being able to buy twice as many clones makes up for the occasional dud. You're also helping to support future development of new boards and software.
The kits are the easiest way to get started, only downside is you might end up paying for a few parts you don't use compared to buying individually.
I can confirm, the dryer will have the amperage it uses on a sticker on the back or it can also be found on the manufacturer's website and as long as it's less than what the cable and outlet are rated for your good.