To create Transaction Iview or not to

Hi All,

I have a requirement to provide material master functionality through portal .The standard MM01 transaction will not suit our requirement we need to do some modifications .I am in a dilemma whether to create a new transaction in ABAP and integrate as transaction iview or create a webdynpro applicaiton and call the back end BAPIs.

Can some one provide the pros and cons of using one over the other.

Regards,

Tarun.