We've come a long way (photo Men's Wearhouse)
She's seen the future (from Trad Private Collection)
A Gentleman's Wardrobe by Paul Keer 1987 (click to read)
ABC of Men's Fashion by Hardy Aimes 1964 & 2o07 (click to read)
Duke of Windsor's Morning Suit from Sotheby's Auction Catalog
Gentry Magazine Summer 1952
Did you get all that? It's not difficult. Morning Dress is worn during the day. Before 5PM and not after 7PM. Most Morning Coats will have a peak lapel but Brooks Brothers sells a Golden Fleece Morning Suit with notch lapel. Not sure why that is. The tails of the coat should end close to the break of the knee.
Trousers are wool and I recommend you buy as light a wool as you can find. A Morning Suit can get pretty warm. Waistcoats are offered in linen as well. Boots work well and you don't have to sweat the color of socks. I'm just not into seeing socks with these trousers -- Checked or striped.
An earlier comment suggested a shirt with detachable collar. They do look better but I gave my only one away. Check out Keezers in Boston, Hornets in London and eBay (including the UK) for significant savings. You can buy decent kit for what it could cost to rent that train wreck up there from Men's Wearhouse.
Will it sit in the back of your closet collecting dust? Mine does, but I know it's there and that's comforting. When my boss is chewing my ass off I can lean back in my chair and think of my Morning Suit while I contemplate his Cole Haan kilties and my new found poverty.