I had new discs pads calipers and fluid the other day spent about £300. When I brake it feels like when I had the old set on. Is this because they need bedding in time or have they left a greasy film on the discs??

Maybe they've not been bled properly? The pedal on mine feels very firm and did from day one when I replaced the discs and pads.

New discs, pads calipers and fluid should leave you with a very solid pedal on a Stilo, with very little free travel. Stilos have good brakes! Is there...
(1) too much travel (spongy pedal), or
(2) pedal is firm, but just weak brakes/need to press really hard?

(1) could be air in the hydraulic system (needs bleeding through with more fresh fluid).
(2) could be protective grease on the new discs, which should have been thoroughly cleaned off before fitting. If it's not been, then the grease will have contaminated the new pads too. Another possibility is a failed/failing servo (or a servo vacuum leak) which would give a firm pedal but little or no servo assistance.

if its all brand new its going to need a good few hundred miles to bed in. avoid any harsh braking events that might glaze the pads whilst bedding them in.