Guidance required on LC

Hi,  I am an small new exporter from India.... i am operating an order through one of my Indian agent who deals with Chinese...  i opt for a 100% sight LC but they offer for a back 2 back LC or transferable LC without divisible clause....

I need your valuable guidance to know whether the above LC's are safe and eligible for taking a bank loan against to it .

Wish to know any other valuable inputs on this

thanks

suresh.ss