In theory, a 700w psu should be ok for sli GTX460.
However, most such units will have the needed 4 6pin pcie connectors if the psu is capable of delivering sufficient power to drive all 4.
Your psu may advertise sli capable, but that is only good for cards that require only one pcie 6 pin connector.
Still, it is worth a try.
You could free up your two molex leads by using an adapter to convert the fan's 4 pin molex connector into a 3 pin cpu header connector.
One like this:http://www.amazon.com/Ultimate-3Pinto4PinAdapter-3-Pin-4-Pin-Adapter/dp/B000BSJGL0
Or, your psu molex leads will have more than one 4 pin molex adapter on the string.
I see little wrong with having both the gpu 6 pin adapter and a fan adapter on the same lead. A fan takes very little power.