@TomTomBinks,
TomTomBinks wrote:All the newer toilets are low-flow. Try to get the highest flow of the low-flows, otherwise you'll be flushing twice.
Last I knew (I admit that it has been awhile since I've heard, so things might have changed) you could still buy new 3½ gallon toilets in Canada and legally bring them back over the border to the US.
I also understand that there is a black market in old 5 to 7 gallon toilets removed from old buildings. I know nothing of how to get into contact with this black market however.
There are also a number of rankings of how various low-flow designs perform. Tsarstepan already mentioned Consumer Reports.
Consumersearch is another good site. They compare Consumer Reports with a number of other review sources (and even customer reviews on sites like Amazon), and try to come up with a consensus among all reviewers.
http://www.consumersearch.com/toilets
http://www.consumersearch.com/toilets/how-to-buy-a-toilet
http://www.consumersearch.com/toilets/best-standard-toilet
http://www.consumersearch.com/toilets/best-low-flow-toilet
http://www.consumersearch.com/toilets/best-dual-flush-toilet
http://www.consumersearch.com/toilets/reviews
In subjects where I am highly familiar with the product category being reviewed, I would give Consumersearch a B+ grade for their quality of review. They aren't perfect, but they are pretty good overall. And considering the difficulty of knowing where to go for an A+ quality review if you are not already familiar with the subject, it is nice to know you can always get a reliable B+ review for subjects that you are not familiar with.
Once a long time ago there was a plumber on the news for having a toilet ranking page. I believe this might be him (though I'm dredging my memory here):
http://www.terrylove.com/crtoilet.htm
This guy is also one of the sources considered by Consumersearch.