Hi there, this is where i bought my HIDs from:
http://cgi.ebay.co.uk/Xenon-HID-Conversion-KIT-H1-H3-H7-H11-HB3-HB4-9006-H9-/220486482784?cmd=ViewItem&pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item335604bb60#ht_5471wt_941
They come with a 2 year warranty, although i've bought 3 kits from this seller now and i've never had any problems.
As for mounting the ballasts, i know a few people have mounted them in different ways, but i personally used the tape that you use to stick number plates on with and mounted them in almost the exact same places as Parthiban:
Mine are 6000k and i would highly recommend them as they are mainly white with a slight hint of blue, and they light up the road really well (not as well as 4300k, but i personally prefer the white/blue colour of the 6000ks!).
Its really down to personal preference when it comes to the colour though imo :)
Hope this helps
Rich