Brompton owners

Just started a new job and they are buying me a new Brompton.

They have stipulated a couple of things that they want me to get so that I can pass the bike on at some point.

What they have specified is:
M type (U shaped handlebars)
6 speed
Version R - mudguards & rear rack
Plain black
Kevlar tyres
Battery light set
Touring pannier

But having spoken to my line manager, there's some leeway in this. Obviously the rack is removable and I can modify bits and bobs.

Ideally I'd get an S2L, but I think the 6 speed is a definite requirement, so am looking at S6R. No-one has what I need in stock, the closest being a P6R.

Is rear spacing different on the 6 speed version?
What is the different between the S type and P type front support, could a change of handlebars on a P give a similar riding position?

Also, I'm 5'11", would I need an extended seatpost?

Go for the S type a lot sportier feel. You cannot change bars after.

You will not need the extended seat post unless your legs are disproportionally long. I'm 6' and the seat post is perfect at full extension so never have to adjust.

Get the front bag, even if you have to pay for it yourself.