Is there a Technic set that is just an assortment of parts and not a specific vehicle? Can I buy Technic sets that are just assortments of parts as opposed to a specific vehicle?

Background

I do research on sediment carbon cycling in lakes and I need use a rotating array of magnets to keep the water from stratifying in my incubation cores during experiments.  

The cores are arranged around the rotating magnets and there is another small magnet suspended in the water of the core tubes.  The slowly rotating magnets cause just enough movement in the internally suspended magnets to induce some flow in the sealed cores. 

Basically I need a setup that allows me to make slowly rotating horizontal ferris wheels of various sizes.

Historically I have built these setups from wood and small motors but I have begun to think that Legos would make a better and more flexible tool.

It looks like Technic sets are basically what I need (although other suggestions would be welcome) but I just want some basic parts not a cool truck or dune buggy.  I have looked on the Lego Technic webpage and all I see are cool vehicles.
Lego sells several kits of parts through their Lego Education line. You can buy them online in the US here: http://www.legoeducation.us/

The direct link to the Technic kits is here:
http://www.legoeducation.us/eng/characteristics/ProductLine~Machines%20and%20Mechanisms

They have a $50 "Simple Machines" set, a $140 "Simple and Motorized Mechanisms Base Set", a Pnuematics add-on set, and a very cool Renewable Energy set (yes, there is a Lego-branded solar panel!).

Also, if you look under the parts and accessories section (http://www.legoeducation.us/eng/characteristics/productType~LEGO%20Spare%20Parts%20and%20Accessories), you can order variety packs of various parts (e.g., 5 each of each length of the studless beams).

Caveat emptor: I have not compared prices to Bricklink.com, where you can also buy pretty much every Lego element ever molded in bulk quantities.