plist or sqlite
Plist and SQLite have different use cases.
PList is a file format used to store a small amount of structural data (less than a few hundred kilobytes), typically a dictionary. PList doesn't have sorting capabilities in and of itself, although code can easily be written to sort it.
SQLite is a full-fledged database. File sizes (on an iphone) are essentially unlimited. Sorting capabilities are built in. Querying and relational table designs are possible. Performance should be as good as any sorting algorithm you might come up with.
I have not compared the performance of plist vs sqlite, but if you are storing "huge data" as you say then you will benefit from sqlite. Especially if you are going to be performing complex queries, extraction, searching and sorting etc..
From your breif description I would recommend SQLite, but I can't answer your question regarding performance.
Regarding an example on who to use SQLite on the iphone. Apple has a sample on how to do it here