I visited the site you mentioned since we have not used the supplier ourselves it would be difficult to say exactly how safe and reliable they are as a supplier. The reviews in the link you gave, are mixed reviews a few good ones and others not so good. But you have to take note that reviews are personal opinions and are often subjective - unless you know the person who wrote it you cannot really ascertain its validity.
Chennaibazaar has been online since 1998 and they do accept PayPal under 'Pioneer Tradings Ltd'. I tried a mock purchase and was lead to the PayPal page of Pioneer Tradings Ltd.
I would suggest contacting the supplier and get to know them a bit more, ask the questions you need answered. Then decide if you feel comfortable buying from them or not.
All in all they seem like a legit supplier.
Hope this helps :)