Nice Job!!The text is really cool - although it would look better if it was more in the middle. Also - a nice little drop shadow on LBJ would of improved it even more. But overall - this is FOR SURE your best, that's actually a decent sig. Keep on practicing - you're improving nicely.
Text is creative but I'm really not sure about it. it fits well with this sig I guess but you'll rarely be able to pull a font like that off. The pic effect is good but the bg looks like all you used was a few stocks, color balance, and lighting(which needs a lot of work.) It's your best though so keep working at it.