Yeast Quantity

I seem to be getting roughly 3-5 oz of actual yeast from my harvests (3.5-4.5 gal yields). According to Mr Malty I am nowhere near sufficient in quantity. I do not see anywhere a way to figure out the size of a starter I would need to bring the number up to reasonable levels.
3-5 oz seems like a low yield to me from so much trub...

As an aside, I intended on harvesting WLP001 from a pale ale I just bottled. Would that be too dark and strong to use for a blonde? The pale was 5.2% 7* SRM w/ 35 IBUs from Centennial, and the blonde is 4.8% 6* SRM w/ 19 IBUs from Willamette, though I could swap it out for Centennial as well.

I would just make a starter according to MrMalty, and pitch some of the slurry from your harvest. If you want to be extra sure of cell count, make a starter that's half the recommend size, ferment and decant it, then step it up to the full size for brewing. Remember, a SmackPack is 125ml of slurry, you should have at least that much slurry from a harvest. I tend to get ~100ml of yeast solids per ~300ml of wort. I keep my harvested yeast in 300 ml jars, and pitch one jar (decanted, so ~150 ml slurry) into the brewing starter.

I would guess my harvest is nearly the size of a WLP vial. Just make a starter for a vial about as old (my yeast will have been there for ~5-6 wks)?

with older yeast, I'd step up the starter a couple times, I do that anytime my washed yeast is more than a few weeks old. Check with MrMalty or another calc for your starter size, start off at about half that size. When the 'mini' stater is done, cold crash, decant and pitch that slurry into the full size starter. It's not an exact science, but I do this all the time with washed yeast and never have issues from under or over pitching.
If you want to get real exact, there's some info, I believe on Wyeast's site about cell count. You can guesstimate your cell count by the amount of yeast solids you have and use that to ensure a proper pitch rate.