best place for sprites in general is
http://play.pokemonshowdown.com/sprites/ - digging through the various sprite threads is often more trouble than it's worth - if it's on PS, it's usually pretty good in my experience.
- some useful tools for fusions, i've found, which i also just use in general, are piskelapp.com and pixlr.com - free and with good tools
- more than 20 colors gets weird
- where applicable, it's useful to look thru other sprites to find shapes you need, then cut / paste
alright that's all i have time for, unfortunately, since my flight leaves at 5:30 am tomorrow and i'd like to have more than 6 hrs of sleep.
feel free to hmu on PS or disc (miapi#6831) if you need to ask anything more :]