Mariss loves the coolrunner II, a very nice chip however he writes very compact code and wastes nothing, you may need a few more macrocells. 64 should give you plenty. He is doing a verilog tutorial. You may also want to check out the cypress PSoC, analog and digital blocks plus a microprocessor on the same cheap chip, plus they have a good stepper reference design. If you can manage sine cos via pwm, midband resonence correction,, low speed morphing, and quiet synchronous pwm operation then go for it; but it will be far simpler to just buy a gecko. If you know nothing about steppers be prepared for a steep learning curve, same for the cpld.