Depends what you'd like to spend really. Fluoros are the cheapest and are fine for personal grows but if you want high yield you'll have to invest in HPS. With standard fluoros you could buy everything from your local DIY store for less than £50. Prices for compact fluoros vary from store to store, and for a good make of HPS for hood ballast and bulb you're not getting much change out of £150-180.

peace