Biggs looks great so far Blitz! I see you decided to stick with the hair flick (I like it better, too) than to use:
The only other thing I can spot is his t-shirt should be more sage coloured than the emerald of his trousers.
I'll have a go at Jessie then, but like I said it may take a while due to work.
EDIT:
I assume I have to work from this:
I'm not sure if it's official concept art, but I like it anyway.
Also, is there a poly limit I should be aware of?