"downgrading" to Windows 7 Ultimate

I just got a Windows 8 computer and I want to downgrade to Windows 7 Ultimate. I've read of people having trouble after simply wiping off partitions and not saving drives and I don't want to run into this problem too.
How do I create a recovery disk of Windows 8 so that if I ever want to go back to Windows 8, I can. Also can this "recovery disk" be a USB flash drive?

About the drivers: can I just copy and paste the partition into a usb flash drive?

Also, my laptop is a Lenovo Ideapad Y410p, and I've come across that it does not count with a space to put in an mSATA III SSD but it does come with a space to install an m/2 NGFF or something along those lines. When will these NGFFs be available for purchase and should I wait to install windows 7 on one of them in order to make booting faster?

How do I go about installing the new OS?

thanks for your help!

 

Your documentation may give the recovery disc making process for that particular laptop. The recovery disc app will tell you what it is capable of (Lenovo makes their own).

There's some M.2 storage for sale, but it's a bit pricy. CT120M500SSD4.PK01 Crucial M500 120GB MLC SATA 6Gbps M.2 Solid State Drive

(I googled "m.2 ssd" without quotes)