Oh man, wish I had seen this thread earlier. I did the firmware hack on my ps2. Downloaded the hdloader and used a pc side program called exploit sender and a copy of action replay max to transfer the file. It was easy download the exploit, connect your ps2 and comp via ethernet cable, set up your comps ip and ps2 ip to be close to eachother, tell action replay to look for online game saves and then run exploit sender. Takes a little messing around with but usually works for me.
Action replay is a good buy as you can use it to get saves for other games, I also use it to get my yearly NCAA Football roster saves/hot coffee mod on San Andreas (not worth it)