I'm guessing that you're talking about this package:
The marker is basically a clone of the Tippmann 98 so you can expect simple performance and solid reliability.
It comes with a one time use Co2 tank so you'll need to buy a HPA tank. They're about £40:
A simple 200 shot hopper, very simple, you can upgrade to an electric loader at a later time. You may need to shake the hopper occasionally but it'll work just fine.
Squeegee: Good to have. Used for cleaning the barrel.
Barrel Plug: A lot of fields prefer if you have a barrel sock. Barrel plugs can often only work if you shoot once by accident because they come off. You'll want to get a proper barrel sock, about £5 minimum:
Tool kit and spare parts: Just a few allen keys and a manual for taking the marker apart. All you really need.
JT Raptor Mask: Like I said, low quality mask. According to reviews the foam is quite stiff, the plastic is a bit low quality and changing lens doesn't seem relatively easy. It is JT so it's related to the JT Proflex in the way that it's very easy to breathe through so that's something. Not great all-round though. So yeah, you'll want to get something of higher quality.
So to round up:
The package is £115
A simple 48 cubic inch, 300 psi HPA Tank is about £40
A barrel sock is about £5
So you're spending about £160 on all that leaving about £40 for a new mask.
I usually say that you should spend a minimum of £50 on a brand new mask. The cheapest mask I can find that I would describe as good would be the JT Proflex at £57. However you seem concerned with coverage. Getting shot on bare skin on the head is pretty painful. The Proflexes aren't too great for that since the ear pieces are pretty much just fabric. There are full coverage masks but take my word for it; they're not very good. I would say try looking into getting a nice, thick beanie hat of some kind, a lot of masks fit really nicely over a Trapper Hat (you can look it up, I wear one in the winter) which is great for protection and getting paintballs to bounce off your head.
So yeah, looks like you may want to raise your budget so you can spend maybe around £60 on a mask. You have a lot of options in that price range and even more if you go up to £70. For choosing masks there are a few threads on this forum about it.
Short version of my advice is: Go to your field to play on a walkon (Wear your JT Raptor mask, just as good if not better than rental masks), ask around players with their own masks if you can try on their masks for fit and comfort, make a list of ones that you like, go home and look into prices and such.
There ya go
Hope this helped