Kenyon would be great. Free up Bass and/or Wilcox as trade bait.
I'd rather have Bass and Wilcox play than the wash up-often injured Martin. 
I'd rather have Bass too. He's no slouch, and he is perfect off the bench. I get the feeling Bass is more receptive to that role than a loud-mouthed Martin.
Martin's not the shooter Bass is, but he's a better defensive player (more range, better quickness, smarter).
I like Bass, but if I had to choose between just Bass and Kenyon Martin and a player at a position of greater need acquired with Bass's attractive contract then I'm choosing the latter.
Without Jeff Green, we are short on trade assets to improve the team further this year. Transitioning Bass from key rotation cog to attractively priced surplus PF would be nice.