I just spent a lot of time looking for analog arcade joysticks for an xbox360 control panel.
There pretty much isn't anything out there except the Happ ones and similarly priced industrial ones.
http://na.suzohapp.com/all_catalogs/joysticks/50-2875-00I'd recommend getting the 100k version if you go that route, but I have a feeling that the price of the u360 is going to be a lot more attractive to you.
Unfortunately, it wouldn't work for my purpose.
Seimitsu had a nice 10k one in their brochure once upon a time, but no one seems to have ever seen one in real life.
We had multiple people checking with distributors and repair shops in Japan and never came across a single one or part for one.
These little guys used on the Quasimoto control panels turn up occasionally.

I ended up using ALPS 2D 10k joysticks purchased from ebay and making adapters to fit them with Sanwa bat-tops.
They are pretty small and the springs in them are light. I don't think it would hold up to arcade style use.
We ended up going with them because they were already bought and paid for.
Build thread here:
http://forum.arcadecontrols.com/index.php/topic,128941.0.html