I'm not going to offer anything else here, just wanted to say I've come across this 'problem' many times and have tried to work a way around it.
SIM for me is overkill, as you say, when you just want to be alerted to any HDD failures etc.
Setting up the iLO is an option, but can you do any alerting without the (overly expensive IMO) advanced license?
I dont know why HP dont just release a version of the System Management Homepage for ESXi, that would make things much simpler!