usually the best way to do this is in "Passive Serial mode"
One of the Quartus outputs available is a .RBF (Raw binary File) And the Passive Serial mode looks like an SPI device.
You may have to do an Endian Swap on the RBF, but you basically shift the data out, make sure you get the config done and go.
We do this we several designs with various Cyclone and Stratix families.
One thing if this is a new board, and you have a choice, I suggest moving to the newer Cyclone III family, It will give you a faster design, lower power, and at a lower unit cost.
The maximum bit rate is 20 Mbps on Cyclone (If I remember correctly) and 20 or 40 Mbps
So you can figure it as the worse case number of bits for the device. Usually it's pretty fast, unless you have a really slow SPI.
Pete