Buying a PSP from Success-HK AKA www.yesasia.com/?

Hi, I live in the UK and I'm thinking about purchasing a Japanese 1.5FW PSP from Success-HK,
www.yesasia.com/?. There are afew things that i would like to know first though.
Firstly how reliable is Success-HK when it comes to delivery, how fast does delivery usually take and will i be charged import tax or customs or anything like that?
Secondly I know that using Cusom Firmware you can trick your PSP into thinking that it is any region that you choose so if I set it to Europe then can I install a UK firmware and will it still be set to europe if I downgrade back to a UK 1.5 firmware?
Finally will I have to change anything with the power cords like should i buy a UK one from eBay or just use a converter?
Also if there is any other reliable sites selling PSP's of any region for cheaper than £90/$185 then please let me know.
Thankyou.