Bigtallfatbloke said:
Groupset is entirely up to you. Being on the tall side you'll want either the 172.5mm or 175mm crank length. Take a look at what length you are running at the moment and if it's comfortable stick with it. I'm not sure 2.5mm makes a big difference either way.
The rest depends on how fit you are and/or whether you'd prefer a compact or triple. Personally I'd get the compact with a 12/25 cassette but you might want a triple to make the hills easier especially if you plan on carrying extra weight in the way of panniers. I notice the groupset comes with a braze on front mech so you'll need to budget for a braze on adapter (the one for 31.8 seat tube diameter).
For the rest, here's a few ideas, but have a google and see what bargains you can find.
Headset: £23 or £30. Loads more out there for similar prices just make sure it's integrated 1/18th with 36/45 angle bearings.
Bars: £30 I'd recommend oversize ones (31.8mm clamp), they are generally stiffer, handy for larger guys like us. What width you need will be a combination of personal preference and your shoulder width (probably the 44cm ones going by your measurements).
Stem: £27. Make sure that if you get oversize bars you order the oversize stem.
Saddle: These are a very personal thing but the Charge Spoon gets good reviews for something so cheap. £20
