A guy friend told me that males don't take text messages too seriously. So I wouldn't give him a whole page of written information. And if you did send him that long letter, he would probably send a one worded answer back anyways. They don't communicate like girls do as much. I would suggest to give him a cute short sentence or two... That way he'll get the message and you won't feel so bad if he doesn't communicate to you, via text, as well as you hope or would like him to.
Texts are boring, although I love texting my girlfriend, when I went to boot camp her letters were like gold to me and they still are. I kept them because she sat down and took time out of her day to write a letter to me on actual paper, not some screen that she's been looking at all day.