I believe there is no difference between the W700 and W701 UltraNav(Touchpad) clickers. In fact, I believe the two laptops share palmrests- so if you have a more basic model without the digitizer, color calibrator and stylus, I think you might have an easier time finding it. I'd like for someone else to confirm this.
As for the dock, the dock in particular that you want is the "Thinkpad W700 Minidock V2". This is the ONLY dock that works with the Thinkpad W701, and it works for the W700 as well. No other Lenovo docks(2503/2504/2505, Series 2/3) work with the W700, because it uses it's own interface apart from other Lenovo laptops. Because of this, the W700 Minidock is extremely rare and quite hard to find on it's own. They're on ebay from time to time, but usually not for any less than $100.
Beware, there are two versions of the W700 Minidock: The original, or "Version 1", which ONLY works with the earlier W700 and doesn't work with the newer W701. The "Version 2" is the one you want, it expands on the Version 1 by allowing you to use the W701 with it, and you can also still use a W700 with it. The tricky part is that both dock versions are physically similar, the only difference is the label on the bottom reads in small text exactly what version you have: "Thinkpad W700 Minidock Version 2", and on the top where you put your laptop on, the docking instructions shows labels that display icons for both the 170W charger and 230W charger of the W701. The other difference (best way to tell apart when buying one from an online seller) is the Part No.
Here's the part numbers as seen on the Lenovo website:
Part numbers for Version 1:
http://support.lenovo.com/en_US/product ... MIGR-70422
Part numbers for Version 2:
http://support.lenovo.com/en_US/product ... MIGR-73458