Just look for anything with a small engine as possible (sub 1.2) - Fiesta, Yarris, Corsa are all good shouts - part of me thinks that anything German is likely to have higher insurance, but that's only a gut feeling with nothing to back it up. Equally, 1/2 of me says to get the newest car you can afford for reliability, but the other (cynical) part of me think that the chances of it being crashed within the first 24 months is so high (not a go at you, just reality), that it probably doesn't matter... Get a couple years NCB on a 1-1.2 car and then upgrade to a 1.4-1.6 down the line.
insurance comparison sites like gocompare, comparethemarket, moneysupermarket & confused.com are all a good place to compare cars. But googling young driver insurance suggests a few specialist insurers might help, and you'll probably have to give them a bell for a quote. So, find a car that cheapish on the comparison sites before phoning up specialists?
And, what's wrong with a black box, if it keeps the costs down? Surely it will "encourage" you to be a bit slower if you think you're being monitored - is that a bad thing? A lad at work had one and said it wasn't the end of the world.