Okay, be prepared to do a lot of reading.
Personally, the raptor and DDM kits are virtually the same and 6000K is the most popular HID color when upgrading. 6000K is basically pure white with a slight bluish hue to it. 4300K is OEM HID color and it is slightly more yellow than 6000K but also has great visibility. Anything above 6000K will actually cause your to lose visibility so stay anywhere between 4300K and 6000K.
35W and 55W versions are basically summarizing the power that the ballasts put out but the bulbs for each kit are exactly the same. 35 Watt HID kits will not have the same potential of light output that the 55watt kits would have. I ran a 35 watt HID system on my low beams for a very long time and I can assure you that they were very bright. I switched to 55 watt ballasts and then they just got very bright. Either way you can't go wrong.
DDM does not install the Angel Eyes from their factory but basically give you a kit. Their standard AE's are basically CCFL (cold cathode fluorescent lighting) and the rings need to be bakes in an oven to basically activate them. CCFL technology is ancient and no one really uses them anymore because they not only have cold start issues but also require to use inline power inverters to power them. I had CCFL's back in the day and they SUCKED.
I upgraded about a year and half ago to LED angel eyes and they are a huge improvement in terms of performance and aesthetics. In terms of Angel Eyes on the market for the E46 I am a huge fan of Umnitza's Predator Orion V2's. I have them installed on my car and they are incredibly bright whether it's the night or day.
Umnitza also sells a complete kit (DEPO P46 headlights, HID's, Angel Eyes (preinstalled if you want but installations is very easy), and a DDE harness for the angel eyes). Click here to check out Umnitza's E46 headlight package
I know I wrote a lot and some of it is probably not the clearest since I am using acronyms so I'll make a list here below...
DDE - daytime demon eyes
AE - Angel Eyes
CCFL - Cold cathode fluorescent lighting
I hope this all helps.