Well enclosed is always best as stated in my 'Big Induction thread' as they are totally enclosed and are protected from engine bay temps and there for greatly reduce Heat Soak problems.
www.kam-racing.com should be able to do you the RaceLand enclosed scoop for under £100
You will be able to pick-up cheap unbranded Open filters off eBay for that money but unless your looking fot it just to look good, getting the very best out of a Open filter takes alot of mucking about with trying to get it as far away from the engine as possible and its just easier to go for the enclosed.
Either go direct to Kam-Racings website or pm Kam-Racing from on here.
Mines a Green which is 90% the same, Kam-Racing can also upgrade the cone inside to a much higher quality Green item for an extra cost.