I'm starting play in a high level Deathwatch game soon, and I have a character to make.  It's very much power level, in that I'll be set a character with 50,000 xp to spend.  I'm going to make a techmarine, with the keeper of the forge speciality for one of his ranks.

Being unfamilar with this speciality though, and having a -lot- of xp to spend, I was wondering if anyone could offer me advice on how to build him. :)

It's also possible he'll possess a relic item, so advice and suggestions there too would be welcomed!

 With Techmarines, I would go for durability. You should be one of the "tanks" of the party in that you can take tons of damage and tie up bad guys from attacking other people. I would either pick Iron Hands as a chapter (because they make a handful of your techmarine advances much cheaper, some of which benefit you in combat) or  combat chapter like Blood Angels, Black Templar, Howling Griffons, Carcharodons, Storm Wardens, Space Wolves (using the Errata).  Also, since you won't probably have extra shooting talents for bolters, I would grab a specialty weapon like a flamer, melta, or plasma; this will be a good compliment to what your party will most likely have (bolt weapons mostly). Also, get the Servo-Harness asap and the Omnissian axe. Those are awesome Techmarine items and totally worth getting when you can.