I'd personally like Heavy Arms, Zeta, or Impulse, maybe Sandrock, or even rock OG gundam. Seed isn't that great I know, but the Gundams themselves were fantastic if a bit OP.

Oh and I dunno why but I feel Xavier would want to be in a pissing match, I'm like he needs to be quieter and subdued then bam make him get into a pissing match with Carn. It might be Carn's standoffish attitude I dunno lol.