In the Toto Promenade line, there are still a number of Round Bowl Universal Height toilets out there. Look for CST423SF [or CST423SFG with Sanagloss coating, a little more expensive]. Those are 1.6 gallons per flush. Then there is the Eco-Promenade round bowl, which is the same thing only with a 1.28 gallon per flush tank. That model is CST423EF (or CST423EFG with Sanagloss).
If you can do without the round bowl, you have a lot of options among recommended Totos. The Drake, the Drake II, the Ultramax II, and many more are available in elongated. However, I know you wouldn't be asking about a round bowl if you didn't need it.