http://www.ebay.co.uk/itm/620W-Antec-Neo-Eco-Modular-PSU-82-Eff-80-PLUS-Bronze-EPS-12V-Quiet-Fan-ATX-/121210213697?pt=UK_Computing_PowerSupplies_EH&hash=item1c38b11541

http://www.ebay.co.uk/itm/520W-Antec-Neo-Eco-0-761345-285209-Modular-82-Eff-80-PLUS-Bronze-SLI-Cross-/360786073970?pt=UK_Computing_PowerSupplies_EH&hash=item5400869972

Which one is good for 2-4 boards?
For mini plane...? How many 6 pins PCIE connectors is needed?

Or any other cheap suggestions for UK?