I run Smith I/O for day and night. Most of my riding is at night and the Sensor mirror lens is ok. Yes I would prefer a clear lens for night but it isn't a big deal. Plus you can find them cheap and brand new on ebay. This will cover all your needs.
Smith I O Gray Alexandrite Goggle w Ignitor Lens | eBay
I use the I/O also and love them.
A pet peeve of mine is fiddling with changing lenses, especially while on the hill. Bought the I/O for it's easy lens swapping feature and it's definitely faster and less of a hassle than other goggles I've had.
Sol-X Mirror and a Sensor Mirror are all you need for them. Although I too would fancy a clear lens for night.