Pam Pennick has a blog and is a designer....might be expensive!
Linda Wall works at The Natural Gardener and does consulting. She charges by the hour (seems very reasonable) and is knowledgeable about our funky Austin dirts. She has a blog,
http://www.theredneckhippie.co... that'll lead you to her consulting business. We had her speak at our garden club about growing tomatoes from seed. She's great. If you go to her blog, scroll down past her instructions for making a raised bed to the Jan. 27th entry. She posted about her presentation at our garden club. We loved her!!!
Check out some of the Austin gardening blogs too. Central Tx Gardening has a website and lists gardening blogs. Some of these are also consultants.