That is a good question. In my opinion Jenny Sheppard would make a good switch, she is headstrong and stubborn, qualities that would make her a good, firm top or a challenging and enjoyable sub to take down.
Kate also would make a good switch, she certainly has tried to be toppy, but always end up subby xD.
Thatís on the girlís side, as for the malesÖHmmÖ Gibbs is a top and I donít think he would sub for anyone, Tony maybe, given the right moment, not always, just when Gibbs really needs, because seriously, that man needs a break after being so badly hurt. Surprisingly enough I can see Gibbs letting Franks top him, Franks was there when his wife died and has probably seen all of Gibbs ugly sides.
Having Rodney top around would beÖ disastrous. I mean the man has the ego of an entire galaxy! He would be too demanding, paranoid and impatient. John could switch to, but not to everyone, he doesnít react well to authority, so it would need someone he trusts and feel comfortable with. Carson would make a good switch too; he is very easygoing about and forward.
Tealíc too would be a good switch. He just have that quality that could make him a very obedient sub or a very loving and throughout top.
Thatís what I can make up for it.