Sanga was an awesome keeper/batsmen and would still be if he wasn't the best batsmen the island has ever produced. Due to his exceptional batting talent, he has been give the opportunity to focus on one aspect. Sanga is 30 at the moment, his latest batting form could also be put down to being in the peak of his career.
He batted at 3 when he kept,coming in very early in most matches. Gilly on the other hand came in alot when the score was well over 300.
Prassanna Jayawardene is not an "up and coming player" he has been around awhile now. He is arguably the best gloveman in the world, but his batting has alot to be desired. The best young batsmen in the country Kaushal Silva, is also a keeper and will take Jayawardene's spot very soon i hope.