Tire issues

My '93 Accord has been exhibiting significant vibrations and even some
shimmying as of late, especially at highway speeds. The vibrations were
slight last fall, and rotating the tires did not help. When I had the
winter tires on it this past winter, the vibrations were non-existent. And
I always check the pressures once a week.

Which is more likely: One or more tires are out of balance (or are just
crap), or one or more rims are bent? The tires are Goodyear Regatta 2's and
they have about 10,000 miles on them. I don't know if the rims are the
originals or not (I bought the car used in 2000).

I've been considering new tires if these Goodyears won't balance, and I am
almost sold on the Toyo Spectrum. But has anybody ever heard of Regul
tires? My Accord had Regul Questa's when I bought it, but they were
replaced after I drove 35,000 miles on them. I remember them having good
handling, a good ride, good dry and wet traction, and they were reasonably
quiet. But I can't find much info about Regul, so I don't know if they are
good tires or if I was lucky. If they are a good make, I may consider them
again (one local tire dealer sells them).

Comments and suggestions would be greatly appreciated.