can I ask what are the images are of, and how close will people be when they look at them?
an a200 image can be enlarge to 1m (roughly 3 feet for those stuck on the old measure
) without any real problem,
if it's going to be used a background eg behind a presenter giving a speech, I would think it'd be fine
the print lab might be able/willing to do a small test print at the equivalent enlargement level to see if it's suitable (my usual printer does that, and I've rejected some and accepted some...)