I would suggest after getting goggles getting a 68cu 4500k tank. May stretch your budget a bit to do it but would save money in the future needing to upgrade it.
I would disagree - spending an extra £100 on an air cylinder would take half his budget, or buying second hand at an average of £80 would still take a chunk from the budget.
3000psi fills are available the majority of the time rather than 4500psi. My opinions on why to buy 3000psi standard cylinders and why to buy 4500psi fibre cylinders are all over the forum.
Things to spend the money on are:
Decent comfortable goggles - new or if secondhand be prepared to replace the lens
Standard 3000psi cylinder £30 / £40 new
Decent new or secondhand hopper - No need for a rotor etc, but good hoppers can be bought reasonably new or secondhand
Gun of choice
Pods & pod belt or vest & pouches
You don't need to buy a tournament gun for the option of tournament or woodsball, but because it will be a good all rounder, and ergonomicaly designed for paintball