I recently finished a Vulkan conversion for a friend of mine.
There were a good number of bits that went into this guy along with some extensive greenstuff work. I ended up greenstuffing scales on his cape, the trim around his lower legs, his front tabard, chest plate, belt buckle, both shoulder pad icons and some power cables that run along both arms for the additional equipment he's carrying.
As far as bits, most people can probably recognize them but he started with the Commander boxed set and I used a loyalist Terminator Thunderhammer right arm along with the blade from a Chaos Terminator autocannon for his staff.
The flamer/gauntlet was a little tougher to do. I used the front end of a flamer and the engine from a chainsword to make a "correct sized" flame thrower that mounted under his left hand. I tried a number of things that were too big before coming up with this solution. A greenstuff power cable completes the illusion.
The base is from the lava line over at Dark Art Miniatures.
All in all he was a fun model to do and I think he stands out a little bit from the rest of the Vulkan models out there. There are so many out there these days, it can be tough to come up with one that stands out from the rest.
UPDATE: I was sent this picture of the finished model by my friend.
Some additional modeling links:
Vulkan Hestan conversion by Heroes of Armageddon