What make were you trusty socks? Can you get the same type?
The 1000 milers are fine and if they're the two layer socks then the inner layer is designed to fit quite snug (though not uncomfortably tight). As long as they're not uncomfortable then they should be fine.
I have Bridgedales, Brashers and some cheap Karrimors and they're all fine too though my favourite socks at the moment are made by Injinji as they are designed to separate the toes and I suffer from blisters from my toes rubbing together so I've found them really good.
I have just bought a pair of 1,000 mile socks. They are the right size for me (6-8.5) but were tight to put on and feel quite tight across the top of my feet. Not sure if this is normal, and admitedly this is whole walking around the house with no boots on. But am wondering if they are right for me feet. If not, anyone got any other top socks to buy. I am doing the Thames Path Challenge (50km in 12 hrs) in 2 weeks and my trusty old socks have just worn out. Thanks x