I am 42 and would where some of them (I do agree some will look like tents, but they already do on the models), I am 5'8" and 10st 10lb, if you are less tall probably you will be swamped by the fabric.
I don't think you can get the kenzo look anywhere on the high street, the fabrics are gorgeous and that is what makes it special.
try zara, H&M, top shop and promod which copies the fashion shows. Also some french brands have that kind of ties and gathered effects, my mum wears some similar shape but no idea of the names. (plain bleu, grey and black though)
if you can afford it!