Giant SCR2 - I got mine for £545, so that's within your budget with a fiver left over to buy me a pint for my recommendation
It's handled the Edinburgh potholes wonderfully since I got it in April, comes out well in photos and enabled me to keep up with HLaB for most of Sunday
Last night I even cured the creaky seatpost and this morning all i could hear was the whoosh of the air rushing by as I cruised along Ferry Road. Lovely !
Hopefully the seatpost will now also stay at the height I set it at last night.
If you still want to be a flat-bar jessie, I've seen what looks like a flat-bar SCR2 in the car park at work so that might be more up your street.