Thank you everyone for the suggestions and concerns. Now I know that I can apply for both EAD's ,my another dilemma here now is which one would be better in my situation.
I am currently working in a company in the field that is directly related with my degree and they are ready to file H1-B through OPT but If I can have another 18 months of EAD through TPS then I was wondering if they can directly apply for green-card through Labor authorization process. Which route is quick and easy? Any idea will be highly appreciated as me and my company has least idea in this matter. Thanks again.