You can get 215/40s I believe, but they might touch the arches. (and maybe put your speedo more out than 205/40s)
The F1s are £86.40 on mytyres at the moment, and I believe you get 3% discount for ClioSport if you email them, so they should work out at about £335 with discount.
If you can scrape the extra £35 together then I would definitely go for it! (IMO of course

)
Might cost another £20 or so to get fitted though, so budget for that as well!