not sure which ones you have: dual duty xc - 450 grams dual duty freeride - 575 grams
what you could choose from: syncros ds28 - 545 grams syncros fr ds32 - 564 grams mavic xm 819 - 450 grams mavic xm 719 - 460 grams (same as 819's only not ust) mavic en 521 - 540 grams dt swiss ex 500 - 500 grams
what you should really do is use what you got, save your money and buy a new wheelset. keep the ones you use now as a back up set or sell them and use the money towards a new set. sweet bike btw!!!