Me, personally, I'd go the 1/8th, 5/16th max. I actually fish the 1/16th oz a lot for crappies and perch and do well. It kind of depends on where you are fishing. I'd opt for bigger presentations if it's large deep mud flats, smaller presentations for particular structure, weedlines, shallow sand flats, etc.
I like gold with gold chartreuse for crappies. If I were specifically targeting perch I would opt for something with orange in it, either the gold/orange or copper/orange. Perch seem to prefer orange on the lakes I fish. Either that or it's just a confidence thing since I tend to use something with orange in it for perch most of the time!