sowing letters on is an absolute bitch..use felt - IM WOOLY as his is superbly done.
IM REEVES for a large image of a liverbird.
with regards to size..i wouldnt have it more than 2m in height as u start getting problems of it overhanging the tier below and the stewards kicking off..
material...doesnt really matter, but if its red..make sure it does run when in the washer or fountain!
good luck.