Macbook Air MD 760 or A or B??

Hi

I'm going to be purchasing a MacBook Air next week. I've checked various resellers and noticed sometimes they quote different product numbers.

They vary between MD760, MD760/A and MD760/B. I did the 'livechat' with Apple and they said MD760= SSD, /A = flash drive and /B = HDD, my mate says not so I called the Apple Store. They say poss older models, but all MB Air's have Flash drive (which I thought too).

I'm really confused, can anyone help?

here's a screenshot of the "livechat"