Yep the Marine Hardware one is your best bet. I don't think (correct me if I'm wrong) that you can even get one just like your original, at least not for a reasonable price.
There was a thread not long ago about replacing the rudder with the current MH model, it has excellent seals and no grease fittings (time will tell whether this was a good move on their part, I don't believe in "lifetime" lubrication). Here's the thread: http://supraboats.com/bbs/showthread...rudder+packing
Skidim.com should be able to get you one for way less than $600. Mine was under $400 shipped, I think, with the 10% discount code CCFAN.
Good luck!
1989 Bravura - repowered with 2001 PCM 351 GT-40 - 1.23:1 PCM Trans.
1989 comp - sold
1985 comp - sold