Which new Link mule / card Should I get?

char that has a good link / card would probably be better.

To me, this means Link + Card Mule...
This will be my order of getting link + card mules (only based on how good it is to your DS)
120Kanna (10%dmg & 3%boss) <- both are useful
120Kaiser(15%hp & 40STR) <- *this is not on your list but I still put it here* hp isn't as important but gives you 40 main stat (8level worth of main stat)
120Cannon(10%HP 25STR/DEX & useless card) <- 5level worth of main and sub stat, some survive and
120Lumi(10%PDR & useless card) <- you'll want as many as possible with pdr...
120AB(10sec buff & 40DEX) <- 10seconds buff that will self stun you for 1 sec(unless on rope) with 8level worth of sub stat (not very useful)