pc ideas?

I've purchased ms century of flight. I've tried running it on my ibm
laptop - 256 memory - but not sure if it was the computer or the cheap
joystick - it just did not respond well to inputs - seemed slow.
I'm considering getting a tower pc - used, or build my own. Can
someone give me ideas as to what configuration I need to run the
software the best? The laptop meets the ms stated minimums - but runs
badly.
All suggestions will be very much appreciated - plus suggestions
regarding yokes and rudder pedal set ups?
Cheers,
Pete