Youtube's Rupee Clock
has a playthrough.
I wouldn't watch this movie unless you want the boss strategies spoiled for you. But there are multiple outcomes on who you can fight last.
It's not a ROM or patch, but an epic fangame that has you fighting all eight Rockman 2 enemies at once.
You'll probably have to reroute the controls to your liking.
As you continue to get gameovers, you can get handicaps to help you out such as extra EN capsules and boss Health depletions.