The stovepipe shako was introduced in 1809 to replace the barretina caps. However, it seems the transition took a while and the new shako did not become universal until 1811 at least, all the more so as the quality of the stovepipe was apparently rather shoddy. So unless you're doing an 1812 or 1813 Peninsular army, you can justifiably have a mix of barretinas and stovepipes, though probably not within the same unit.
And no, no light coy from 1809 onward despite Front Rank offering some in stovepipe shakos.