After trying this myself a few times now, I'll give you my honest advice on this - Don't bother.
Even with the correct MIBs to use, you need to rename them into a format that SIM accepts, and then you have to pray that it recognises the traps within those MIBs.
I'd strongly recommend you look at PCM+ instead. Try the 30 day eval. It's designed for ProCurve switches by ProCurve and you'll get a lot more use out of it in the long run.
If you are still keen to give it a try with SIM you can get the required MIB list from the older MIB file -
ftp://ftp.hp.com/pub/networking/software/mibs-feb06.tarThis is also useful:
http://h10018.www1.hp.com/wwsolutions/misc/hpsim-helpfiles/simsnmp.pdfSIM is very particular about the way that MIBs need to be before it will successfully import them.
From my experience you're likely to spend hours on this and still end up with a half baked solution.
If you can work it out though and get a satisfactory result, you'll be hailed as a hero forever.