What you laid out is pretty much the technique, you can find more here:
The secret is in stepping up the volume of wort in the starter. It may take you a couple weeks to get an adequate supply to pitch. I did all of my step-ups in a growler, which is where I generally do my starters. Just kept adding small quantities of sterile wort until you have enough slurry.
I cultured some Bell's yeast last year and it's now my house strain, I use it a lot. Great stuff.
As far as a THA clone, you can probably get adequate results from using either WLP001, or California V. In fact, I brewed a pale ale recently with CaliV and the profile was very similar to my Bell's strain.