I'm afraid that I can't help with plants (me being from the COLD north) but wanted to tell you that there is a gallery where you can post pictures (there is a link at the top of the page). Or you can use photobucket or any of the other photo hosting sites. If you need more help, email me and I can step you through the process.

Kill the weeds first. Then you might want to go with a cover crop until you are sure what else you want to do. I have used rye grain to hold beds over the winter and to crowd out weeds until I was ready. Since you are in TX, you might want to check out the Lady Bird Johnson organization. There are also some native seed companies in TX but I can't recall their names right now.

I do not know the answer to your question, but in certain areas of CA there is a problem with people building their houses on high hills where it unsafe. If unattended, the weeds on the hill catch fire, resulting in nothing covering the hill. When it rains heavily in the winter, the soil comes tumbling down. Now & then we see very expensive houses slide down the hills. Having said that, hillside planting with drought tolerant plants is a frequent topic of concern. Here are some interesting posts:

http://forums.gardenweb.com/forums/load/calif/msg052100451852.html

Manzanita a pretty plant with striking bark although I do know how well it would do in your zone. Here is a discussion of the bush variety:

http://forums.gardenweb.com/forums/load/calif/msg081602282450.html

Here is a very interesting one about ice plant on hills causing gullies underneath:

http://forums.gardenweb.com/forums/load/calif/msg041553507163.html

Along with this forum, you might also search hillside & maybe erosion contron on the CA, TX, & AZ forums.