Brewgyver:
Your controller is made for a Bipolar stepper, which has two field coils, hence 4 wires. The motor with 8 leads is a Universal type, which has 4 coils, 8 wires. You should be able to connect the center pairs to each other. Typically those wires are striped, and if you count the wires 1 - 8, you would connect 3 to 4 and 5 to 6. You first need to confirm the pairs with a multimeter, identify the 4 pairs that show resistence and note the ohms. By connecting the two center pairs, you're converting it to Bipolar. After connecting the pairs, the 2 remaining pairs should have roughly twice the resistance value you read from the individual pairs.
Thanks for the help and the link!