As I said earlier, I am sure that the float switch is rated at 10amps.
This booster pump from machine mart draws 1000w at 230v = 4.5amps.
http://www.machinemart.co.uk/shop/product/details/cbm240-1in-multi-stage-water-pump?da=1&TC=RV-051011130The solenoid valve coils current requirement is very low, so yes they would.
You would just need to confirm with the technical dept of machinemart that this float switch is rated at 10amp to be 100% sure. The wire used looks like it will carry that current.
Make up a cable from 10amp cable with a 13amp plug for your normal wall socket. Run this cable to a 6 terminal 20amp junction box.
eg.
http://www.screwfix.com/p/heavy-duty-junction-box-20a-6-terminal/21209The postive (brown) from the cable would go the the first terminal you allocate in the junction box. Identify which 2 of the 3 cables you need from the float switch. (In a previous recent post, the float switch can work opposite to the way it's wired up in a submersible pump. You need the setup that will switch the current off as the float becomes vertical.) The first wire to the switch will then be wired into this same terminal you put the feed into. Take the other wire from the float switch and allocate it a 2nd terminal. This will be positive only when the float switch is on. You then use this terminal as the positive feed to the solenoid valve and the booster pump. The neutral of both booster pump and solenoid valve will be allocated the 3rd terminal (blue cable), as will the neutral to the plug. The 4th terminal will be the earth cable, used if the booster pump and solenoid valve are earthed. If they don't have an earth, ie they are double insulated (only have two wires) then it won't be used.
The 3rd wire that comes out of the float switch will not be used. Separate it and wire it in to the 5th terminal in the junction box to keep it out of the way. No other wires will be connected to this terminal.
Spruce