I forgot to mention that all the leds are controlled by the wifi switch.
For the sd card mod all you need are:
Micro sd to memory stick pro duo adaptor
Either a ribbon cable or 30awg knyar wire
Sd card socket from a card reader
And of course a sdhc card.
There is a really good and easy to follow guide in the psp phat forum
If anybody needs anymore details on either the sd mod or the led mod just let me kno and ill try and help the best i can