Property Management

I have a upscale condo in the Sukumvit area that I want to lease out on a long term basis. Since I will be out of Thailand most of the time and will not be there to manage the property myself (handle tenant issues, finding new tenant when old tenant vacates, handle necessary repairs, etc.), does anyone know of a reliable property management company that provide such service and what type of fees do they generally charge?

Thanks for your input.