I am sorry, but the best mittens are Army Surplus:
Here is what I use: Please note Army Trigger finger Mittens are issued and often sold without liners (i.e. just the Outer Shell). If you buy one, make sure you get a liner with it. When I was in the Service, we were issued one Shell AND two liners. I would also use a very thin glove liner in temperatures below Zero. Above Zero the issued liners were good enough even on Guard Duty (Where you had to stand around, you get cold quick standing in the Cold).
Here they are in DBU Cameo:
Here is the Arctic Version of the Mittens: I have NEVER used them, the regular Trigger Finger Mittens were good enough till the tempertures STAYS below Zero Fahenheit:
The Army has to much money, thjey seem to have come up with new Mittens in Gore Tex:
Sportsmen Guide is selling these Third Generation Trigger Finger mittens for $29.99:
http://www.sportsmansguide.com/product/index/used-size-xl-us-military-ecw-trigger-finger-mitts-black?a=1100976
Sportsmen Guide is also selling the arctic mittens for $29.99:
http://www.sportsmansguide.com/product/index/new-us-military-surplus-ecws-mitts?a=1787345
Through watch Sportsmen Guide, they are also selling "Flying Mittens" which do NOT have a trigger finger and thus useless if you want to shift gears.
As to the old fashioned Second Generation Mittens and inserts, they are all over E-bay and the net
One place is selling them for $14.99 plus free shipping:
http://www.amazon.com/LEATHER-TRIGGER-FINGER-MITTENS-Medium/dp/B002B93CVW
One more comment, these Mittens tend to run LARGE, for the Army wanted its soldiers to have plenty of room inside them to move those fingers around. Some people object to this larger then normal size, but I used them and see why the Army designed them so large (to get that trigger finger to the trigger without taking it out of the mitten WHILE keeping that trigger finger in the mitten part with the rest of the fingers to keep it warm).
A popular "Modern" Solution (Post 1990, I am getting old) is two finger gloves. I question their superiorty over trigger finger mittens, but some people swear by them:
http://www.odlo.com/shop/eu/en-us/gloves-windproof-two-finger-warm-xc-men-792770-12.html
Through in more recent years I have seen a return to Trigger Finger Mittens, but now called "Three FInger Gloves" for some reason:
http://www.backcountry.com/hestra-heli-3-finger-glove
Thus you have options to handle very cold weather. If you decide on the Arctic Gloves, how cold are you planning to bike in? I recommend the Army mitten, what I call Second Generation. The wool inserts will keep your hands warm and the cotton shell is good enough for temperatures below 25 degrees.