I've got some Merrells and would really recommend them. There's virtually nothing between your foot and the pavement and a 0mm drop from heel to toe. The toe box is very wide which looks a little comical but they are very snug elsewhere.
I got mine from Ellis Brigham as none of the running shops I tried had any 'barefoot' shoes.
You'll have a really hard job finding anywhere that stocks any barefoot shoes. None of my local running shops had any but I did find a pair of Merrell Trail Gloves in Ellis Brigham (outdoors shop) so I bought those.
I'm very pleased with them as they seem an almost perfect design but it would have been nice to try some alternatives and see which I preferred.
Forgot to mention that the pace of 5:30 can be changed to a suitable one for yourself - you're aiming here to average 98% max HR, so the pace needs to be very hard but just maintainable over the distance. It might be easier to start with 400m intervals, if you've not done any previously.
GP - it's mostly 'noise' i.e. a distraction from running, but it makes a good HRM and that can be used in conjunction with distance measure to setup some good training sessions. This is the one that I've found most beneficial :-