I am planning to play Eric Clapton, Hendrix, and, RHCP

I am looking to get more information about pickups. Any websites that you can recommend for me so I can read more information about pickups?

I was looking at several guitars;

http://www.ishibashi-webshop.jp/shop/g/g310109100/ (Japanese one)
BODY： ALDER
NECK： MAPLE OVAL TYPE, 324 SCALE
FRETBOARD： MAPLE ONE PIECE, 184R, 21F
NUT WIDTH： 42mm
PICKUPS： TEXAS SPECIAL (U.S.A.) X 3
CONTROLS & SWITCH： 1VOL, 2TONE, 5WAY SW
BRIDGE： DIECAST BLOCK S5D VINTAGE

http://www.ishibashi-webshop.jp/shop/g/g311653100/ (Made in the US)
Body : Alder
Fingerboard : Rosewood 22 Jumbo
Pickups : 3 HOT SC STRAT w/Alnico 3 Magnets and Revers Wound/Revers Polarity Middle
Controls : 1Vol 2Tone
Bridge : Vintage Style Trem

http://www.ishibashi-webshop.jp/shop/g/g311437200/ (Made in Japan)
BODY： ALDER 2P
NECK： MAPLE OVAL TYPE, 324 SCALE
FRETBOARD： ROSEWOOD, 184R, 21F
NUT WIDTH： 42mm
PICKUPS： CLASSICAL VINTAGE DCS-1 X 3
CONTROLS & SWITCH： 1VOL, 2TONE[CTS POTS], 5WAY SW USA
BRIDGE： STEEL BLOCK S8F VINTAGE

Most all I needed to learn I got from Seymour Duncan's website, especially the FAQ section of the website, in addition to using their forum.
I would start there. I can give some advice, but opinions on pickups are subjective, for sure.
I prefer alnico magnets over ceramic magnet pups - warmer, rounder tone, but people also feel ceramic pups give a vintage tone. Ceramics are good for high gain applications in a lot of circumstances.
For strats, look at alnico V pickups.
For output, you could look at 5-6 dc output for mid and neck, and get a hotter bridge pickup, around 8 or so.
This is what I did for my HWY1 strat. I got the recommendations straight off the Duncan website - SSL-1 for neck and mid, and an SSL-5 for the bridge.
Fantastic sounding, vintage tones, with real mid range punch in the bridge.
Maybe look at the SSL-1 and SSL-5 Duncan pickups first, and see the variations you can do with combining them with other pickups, and then check out the Duncan forum to see what others think.
Pickup selection is very personal, IMO. People like different things for different applications. But, for the music you describe, I think the guitar with Texas Specials may be your best choice. Just my opinion, but I really like Texas Special pickups. Good luck.