Investor seeking realtor and rental mgt firm in San Antonio, TX

[Ash Geria]

I am an investor, planning to invest in rental property in San Antonio, TX and need help in finding a good local real estate agent and rental property management firm. Does anyone know a good realtor knowledgeable in investment property and a reliable property management firm? If so, please refer. 

Any advise regarding areas to target (or avoid) for rental property for an investment will be highly appreciated. I have heard of high crime rate in certain areas so I need some suggestions. 

I'm planning to visit San Antonio, TX on Dec 6-7 to see and select properties. 

Thanks, Ash