We've used USDigital H1-50's for the last 3 seasons. Again @ ~60 they aren't the cheapest, but they are readily available, and support has been excellent.
http://www.usdigital.com/products/h1/
We leave one drive shaft a little longer and then couple the two shafts together with surgical tubing. This helps absorb side loads, etc...
They've worked flawless and never had any issues with them.