I am not clear on the 'smart casual' aspect, but I've had my eye on this one particular trench:
http://shop.nordstrom.com/S/30.....5&P=1
I'd go for the 'royalty' colour - ie. purple. Just for a bit of punch beyond the usual black or navy.
That said, I came across a very similar coat on Overstock (50% off)....almost identical:
http://www.overstock.com/Cloth.....oduct.html
I was eyeing the navy, but what stopped me was the description as a 'spring' coat - plus I noticed that the coat on Overstock was a cotton blend, whereas the Nordstrom sateen version had no cotton. I was visualizing 'more wrinkles' with the Overstock version.
But - check out the nice buttons on the cuff of that Overstock navy blue one - cute!
I was pretty tempted to order the navy one on Overstock today - but then got stopped by the fact that it wasn't quite the same as the Nordstrom one that I really liked. I was concerned about 'spring' and ...'cotton'.
Personally - I think the Tahari "Lola" Sateen coat in the 'royalty' colour as featured on the Nordstrom site is a really nice trench coat. The colour's a wee bit unusual, which I like - plus I can see it being both dressy and casual.