the fan is a SPAL brand. there is no better quality available than that. part # is: COOLING FAN Y0050.02A8A
same number as your original .02A8 with the A being superseded number. the fan is non-serviceable as it is a sealed unit. the ecm controls the high/low feature you mentioned. tons of "how to remove and replace" posts available on here. also pay particular attention to any oil mist you may find on the fan and/or housing. if so carefully check your rear rocker box and cover area for faulty/leaking gasket. while performing the fan repair strongly suggest replacing the O2 sensor while working in that area. yours is 13 years old or more and near the end of its designed lifespan. the following cross over to the buell O2 sensor part:
GM OEM= 25162693
-NTK= 21002
-Airtex= 553071
-Bosch= 12014
-Denso= 234-1001
-Walker= 250-21001
-SNG= SN1-15