Bathroom Refit. from wet room to cubicle

Background:

We currently have a small wetroom W:180cm L:203cm H:212cm which is all tiled ceiling to floor and awful. We are looking to have it all ripped out and a new suite including quadrant shower put in. Plastered (including ceiling) and the floor and shower cubicle tiled. We are based in the South East of England.

Labour
We have a quote for the labour from a company which is £1500 which seems reasonable from the number of quotes we got.

Materials
We have a separate quote for the materials which we are to pay for in advance and it all seems pretty much fine except for the wet room floor drainage system. Not sure what this is and if it is something we need. We have bought all the suite and don't want to double up on materials.

Items we have bought

• Compact white wall hung unit with energy close coupled toilet
• Click Clack Basin waste (Unslotted)
• Vanity unit and counter top basin bottle trap
• Universal flexible toilet pan waste connector
• Universal toilet intlet shut off valve
• Universal toilet floor fixing kit
• Mode cubik thermostatic shower set
• 90mm slimline shower tray waste
• Round heated towel rail 700 x 400
• Mako straight radiator valves
• 6mm sliding door offset quadrant shower enclosure 900 x 760
• Right handed offset quadrant stone shower tray 900 x 760
• Cleanse basin mixer tap offer pack

Material costs:

• 6 sheets of moisture resistant plasterboard
• Wet room floor drainage system
• Drain System
• 3 bags bonding plaster
• 8 thin coat angle beads
• 6 tubes of copper piping
• time grout (white)
• tile adhesive
• miscellaneous such as valves and caps

Total: £404.96

Thank you for reading this far if there is anything you can add it would be appreciated. We are on a very tight budget and desperately hoping not to get ripped off.