I’ve got one and think its fantastic; it worked wonderfully in the Himalayas and the Borneo rainforest in the middle of the monsoon rain. I can’t recommend it highly enough.
I’ve not used it for cycling though and don’t think I would. Not sure why tho!
I’m 6″2 and roughly same weight as you and I got a medium which is spot on. Its got long arms as well which are properly designed.
I couldn’t find a local shop with it in stock either so bought online. I ordered through SD (I think) but it came from Trek&Field (or the other way around); either way both are the same people but one was free postage and one wasn’t so check before ordering.