You have three excellent choices for selecting and buying a toilet:
1. Home Improvement Stores
Home improvement stores like Home Depot and Lowes have a good selection of modestly priced toilets. If they don't have the color you want in stock, they can order it and have it quickly delivered.
2. Kitchen and Bath Showrooms
Specialized showrooms are a great way to see some higher end toilets. These showrooms will not carry all of the high-end brands, so it is a good idea to try several showrooms before choosing a toilet.
3. Toilet Etailers
A number of online companies now sell toilets online, including DesignerPlumbingOutlet.com and QualityBath.com. These sites are well organized and informative. The customer support is also excellent. The most impressive thing is the selection of toilets, which is very extensive.
NOTE: If you are interested in a specific brand of toilet, call the manufacturer for a list of local retailers and internet etailers.