is it possible to get a chip to increase the bhp in this car and if so will it effect the clutch and make it slip? Is it easy to install and will it effect the warranty??

It would be possible.But not worth it,You wont be able to squeeze any more power out of the 1.1
It wouldnt affect the clutch or cause it to slip,Not a diy thing to install,it would need to be professionally done really.
And as for your warranty, any modification at all could mean your warranty is junk.Certainly chipping the car will cause mitsu dealership to not want to touch car.
If your looking to boost your 1.1s power stick to breathing mods such as intake and exhaust. Simple mods like this will give you the best response and not cost you a leg.

and what would you recommend and where would i get them

Well i could recommend specific parts but ive no experience with what works better on the Cz so youd be better off reading actual owners opinions and views.

But try to stay away from the universal type bits they wont be as effective as the big name brands like hks,blitz and k&n

well theres a universal k and n air induction filter in the argos cat i was thinking of getting it to see if it makes a difference or not. what do you think?

Id say no.It may well be pretty good and no doubt it would free up the cars breathing a bit but....it might not give you the max possible.
I just checked k&N website and they only do a panel filter for the 1.1 so with that you would end up keeping your airbox,which you might want if your worried about warranty.
Also checked out the argos website,they dont have all the stuff from the catalogue but i could only find two air filters on the site,neither looked very impressive but their less than 20quid.
Quick search on google shows most of the replacement filters for the 1.1 are just panel filters and nothing else,maybe a unisversal one would be the solution but i still thing you should look for a good name or brand,those cheap filters will look and work great when you put it on but it wont last for long.
Where abouts in the north are you?theirs plenty of decent tuning shops around im sure if you drop in to one theyll show some decent bits of kit you could try.

two words engine swap