im also going to want , 4-2-1 manifold, adjustable fuel pressure regulator
no, you really dont, they have a VERY good 4-1 as standard, you have to be really pushing the envelope of engine builds to need to change the manifold.
as for an Adjustable reg, they are utterly pointless, the standard vacuum referenced fixed pressure 3 bar unit works just fine, you wont gain anything from adjusting the pressure, if you need more fuel get the map altered.
I think I will go down the cams and throttle body options, anyone got any advice for that?
Satchell engineering do a very good kit for the throttle bodies, cams you have to be very careful as there is very little clearance in the standard piston to allow the valves to open earlier, they can be modified by Bridgecraft motorsport engineering to make mild upgrades safe, if you want to go further then you're talking about pistons rods and valve springs.
this thread has lots of information on the cams you can and can't fit.
need a part number? get on here - http://public.servicebox.peugeot.com
Bring on the Trumpets.