Lion blanket idea

Just kicking this one around.
There is a small person in my life who happens to think H. Potter and Gryffindor are very cool.
One project I did for a few people with babies was an intarsia(sp?) knit blanket of nine panels of Beatrix Potter-inspired rabbits. I grafted out the patterns from ideas taken from needlepoint patterns, sewed the nine squares together and backed it with fabric. Not really baby blankets (not very practical); more like wall hangings.
But for this Gryffindor-inspired lion crest (because I'm not going to violate Rowling's copyrights) I was thinking of redoing this idea. Using this version for the chart (I haven't charted it yet) then knitting a 36"x36" or 48"x48" cotton intarsia piece on a dark red field, then backing it with fleece or flannel so it would be both soft and not so likely to unravel.
Seems like the 2 major challenges here are a.) charting the dang thing and b.) finding a nice, soft, 100% cotton yarn that comes in nice, intense colors. Sport or DK weight?
I don't think I have any pictures of the baby blankets, but if I have the charts maybe I'll scan them up.