>>You can go with alibaba trade assurance. You can get performa invoice from manufacturer.
2)How to get Customs clear or entry bill ?
>>Here we use international shipping companies like Fedex and DHL to deliver products on our doorstep. These companies bring product from china to india and also take responsibility to clear it from customs but here they will require your KYC documents (in KYC you also require to provide IEC). These companies will also pay customs on your behalf and when they come to deliver product to your door step then they will take all the custom charges from you which they have already paid on your behalf.
>>You have to provide the kyc document to your shipping company once the product has landed in Indian soil then they will pay custom fee behalf of you and when they bring your product to your door they will give you a BOE (bill of entry) document and you have to pay custom duty which they had paid on your behalf.
>>Have a nice day.