Hi,

Uhmm this one will be ok for 1 Ant. If you think you'll get another ant in the future; you can choose:
http://www.ebay.co.uk/itm/Dell-PowerEdge-2800-Server-POWER-SUPPLY-7000815-0000-D3014-930W-PSU-dw1-/251478903791?pt=UK_Computing_PowerSupplies_EH&hash=item3a8d4f8bef

This one will power 2 ants... It will cost you around 20-22GBP.

One note! These PSU's have a max amount of watts you can use on each output pin.. So if you have a complete ant (both blades) on 1 output pin...then you'll be pulling >360W on a pin that has a max of 312W (in case of the 930W PSU). You'll fry it... like I did