Welcome @Ryne Ray to the Bigger Pockets community.
I think you will find it difficult to find a real estate agent to submit a lot of low offers for rent ready properties here in DFW. According to the Real Estate Center at Texas A&M University the current market (as of the end of July) in Garland has 1.6 months of inventory. Normal inventory is around a 6 month supply. Therefore, Garland is in a strong seller's market. The rest of the Metroplex has very similar supply numbers. You might want to post a question about your approach on the Real Estate Agent forum here on Bigger Pockets to see what type of response and ideas you get from the real estate professionals.
Instead of using the MLS have you thought about doing direct marketing to owners of distressed properties (probate, divorce, etc.)? These people are typically more motivated to sell.
FYI, once you have your license here in Texas you must disclose that you are a licensed real estate agent when you submit an offer. Not only will your reputation be on the line, but there is an expectation that you treat consumers honestly and fairly. You should learn about this in your contract law pre-licensure class.
Good luck!