Unfortunately I don't know anybody else who has a PSP, let alone homebrew enabled.
I'm checking the usual places to see if I can find a pre-made memstick image, and then I'll try using your guide, because it sounds a lot more fluid than many I've seen.
I'm kinda pissed at the whole lack of help Datel have been on the subject. I had hoped this would be something I could finally use properly (I still have a Duo2 for PS2, and Viper Pro for GC sitting around I've never gotten installed or used).
Point of note - don't ever let friends near your PSP when they are unsure of it. Mines was fine until a friend tested it, and being a useless pedantic sod, checked for new firmwares from it - Bye bye Super mario war, hello v3.4 (on both PSPs

)
Anyways, I'll give this a try, and hopefully have some luck.
*crosses fingers*