You'll notice that almost all books listed are eBooks. You are welcome to purchase these eBooks anywhere that pleases you. I have Amazon and Nook accounts and can receive books there, however I prefer to receive them in ePub format when possible.
If you enjoy the act of giving a physical gift, here is how you can give me the eBook. First, download the ePub file from the sites I have shown. Second, burn it to a CD. Then wrap up the CD in wrap.
Obviously you are welcome to e-mail the ePub file to me, or simply send me an online redemption. I am not very focused on exact mechanism. Surprise me. Do what is easiest for you, or makes you happy. It's all good.