Giant TCX frame questions - need info please?!

Hi folks,
Newbie posting - I've lurked on the site a lot since Dan Seaton introduced me and I go to a fair number of races every season, but strangely don't make it too far from the beer tent most of the time ...

Anyway, I scored a TCX frameset on ebay a while ago but it sat in storage for ages while wasn't able to collect it. So now I have it - but it's missing a few important parts that I don't know how to get direct or 3rd party replacements for!

I'd also like to try to get some information about the frame. The number is GE788918 and it was listed as a 2006 model - is this correct?

The first part I need is a headset. The head tube is relieved a the top and bottom to a depth of about 1cm so it looks like it's intended for a semi-integrated/zero stack/press in - or whatever you call them! headset. However, the Ritchey WCS one I bought has cups that are too large to press in. I was directed to the Ritchey by a friend who says he has it on his Giant Bowery so I naively thought it would be the same ... if only life where that simple!

So, does any one out there know what type or model headset I need for this frame?? It's definitely for a 1 1/8" steerer and not 1".

I'm also missing the funky integrated seat collar and cable stop, but I guess I have more options here. I measured the seat tube at the top to be 35.0mm but would that actually be a 35.0? 34.9mm is more usual. Anyway, can anyone suggest where I'd get a replacement clamp, or point me to a source for 3rd party ones. Integrated clamp/stop would be great but I'm sure I can bodge an alternative together if I need to. A matching 1 1/8" steerer hanger/stop would be very pretty too.

Finally, there's a threaded boss at the bottom rear of the seat tube which is where I assume a cable reverser would attach since the F mech cable is routed along the top tube. Should I use this with a convential mech or can/should I use a mtb F mech designed for top tube routing?

Thanks in advance for any input!

Cheers, Gareth.