I followed my heart rather than my head and would almost be embarassed at how far I travelled to get Daisy if it hadn't turned out so well.
I travelled from Ayrshire, just south of Glasgow in Scotland to Norfolk. it was about 400 miles in each direction. My mum and I travelled together and made a short trip out of it. 8hrs drive down, stayed over in a nice B&B near the breeder, they took us out for dinner that night, then picked up Daisy early next morning and 10 hours back home.
It was remarkably stress free. Daisy cried when we tried to travel her in the crate in the back of the car, so we put her at my mum's feet in the footwell of the passenger seat and she slept most of the way home. Stopped every two hours for a break, stretch all of our legs and tried to time that with when she was due her feeds.
All worked out fine. And didn't put her off travelling in the least. She loves being in the car now and goes most places with me. In fact I have to be careful if someone opens the boot of their car - Daisy is in there and looking out the window before you can blink.
All that said, with my sensible head on I would ask if you really needed to travel that far for your puppy and if you couldn't find a good breeder closer to home. But who am I to talk!