I think the best bet is the Nayardeen Ward. Not sure how powerful their ships are but apparently they all look quite similar to the N'Derix freighter and Lendao corvettes. However it was noted that they are significantly smaller than both the Citin Alliance and the Republic of Daranir, so I find it hard to imagine that they would have warships any more powerful. But maybe they have an advantage in weapons technology or something. Or maybe they have bombers with more powerful payloads, or something that would crack the UTC armour.
An alternate options would be another group/faction of the Cirin Defence Force. So another Admiral with a heap of powerful ships.
A farfetched option would be the Creer Syndicate with a heap of corvette size ships that'd be largely ineffectual (unless they're as powered up as the Scarborough, which id doubtful).
An even more farfetched option would be the Souri Collective. The Daranir reported that they had been in isolation from anyone and everyone for over 200 years, but a ship had been sighted a few times in the Darani territory recently and just because the Darani haven't been in contact doesn't mean the Cirin's haven't. A single Souri Behemoth ship should demolish the UTC ships without breaking a sweat if size matters at all... I bet those ships have bloody Lances on turrets *LOL*
P.S. @David: don't forget the Paul Hogan show
, but if you really want to take a bit of Aussie with you, you can't go past the Leyland Brothers (one of their shows has the best instructions for cooking damper I've seen).
P.P.S THE GIRL FROM TOMORROW!!!