Terry's site does not show a 1.6 gpf Drake with Sanigloss, so I check a large online Toto dealer and found that apparently the only Drake 1.6 gpf with Sanigloss is the one in white as you reported. As a confirmed disciple of Toto toilets, I find it hard to say this, but you may want to consider whether how important that feature is. I have had both a 1.6 gpf Drake and a 1.6 gpf Dartmouth neither with Sanigloss for several years. I have not found a cleaning problem with either of these toilets. It may be worth a phone call to Toto CS to see if a special order is possible. As to the insulated tank, this topic has been discussed several times on this forum and the general consensus is with low flow toilets, insulated tanks are of little, if any, value. Here's why. Low flow toilet tanks contain about twice the amount of water needed for a normal flush. This means that the water in the tank will be a room temperature and not subject to condensation. When the toilet is flushed, the incoming refill water has been in the pipes for sometime and is also tempered. Even if additional cold water is needed, it will mix with the tempered water left in the tank. Long story short, unlike the old 3.5 gpf toilets that empties the tank on every flush and required all "new" water and were subject to condensation, low flow models don't have this problem.