In a slight change of plan I decided to, rather than just getting the figures for the first 2 brigades, order the figures required for the entire division; justifying this by telling myself that it made sense to have something different to paint, in this case the blue coats of the Portuguese, if I got tired of painting lots of red...
Selecting the British was pretty straight forward, with the only difficult choice being which pose to get! As nice as the firing line poses are, they don't, in my opinion, make for a particularly realistic set up on the table unless they're within musket range of the French, so with this in mind I opted for the, much more utilitarian, marching pose instead. So, on to the Portuguese, which turned out to be a bit less straight forward than I'd anticipated. Looking at the available figure choices at http://www.fighting15sshop.co.uk/ I was confronted with the option of troops in stovepipe shakos or troops in barretinas! At this point the sum of my knowledge of the Portuguese didn't go much beyond the colour of their coats. The lure of an easy paint job had me thinking "hell, just get the figures in stovepipes", but then the (slight) retentive in me thought "knowing my luck some (even more retentive) self-proclaimed expert, at a show will pillory my inclusion of stovepipe hatted Portuguese because they didn't come into use until 1813 , or whenever...." A quick flick through the bumper book of napoleonic goodness (Haythornthwaite) revealed that the stovepipe style shako wasn't introduced until 1811, possibly to regularize the silhouette of friendly troops at a distance (my mind immediately strayed to a drill sergeant holding up a large card with a silhouette of an Old Guard, "No laddie, these are not your friends..."). Anyway, back to the task at hand; it seems that Barretinas are the headgear of choice for my 1810 Division. They have coloured cords so will take more time to paint than the stovepipes but will, along with their blue coats, make them quite distinct from their British comrades. After this "taxing" exercise I was pleased to discover that they were only available in "order arms" pose, so I added 3x 30 man battalions to my order and that was that.
I research colour schemes; facing colours, tartans etc..