The Corona looks nice. This is a regulated light, with a long runtime on 3 AA batteries. It is intresting that on the highest setting, the light is only regulated for 5-30 minutes. There is a review online at:
http://www.flashlightreviews.com/review ... corona.htm
Some other alternatives:
I have found the PT EOS to be a good light. It is not as bright as the APEX, but much brighter than the Aurora. It is also regulated, giving an even light. The regulated light lasts for 2 hours on high with 3 AAA alkaline batteries. I usually change the batteries after about 4 hours on high. It gives 44 hours of regulated light on low, which is almost as bright as the Aurora. It can easily be found for arround $40. They are rated as waterproof to -1m, and mine has survived many dunkings. They provide more of a spot light. Sometimes this is an advantage, at other times it would be nice to have more diffuse light. There is a review online at:
http://www.flashlightreviews.com/review ... ec_eos.htm
The PT Quad is a little cheaper, available for arround $30. It is similar in many ways to the Petzl Tika Plus, but is rated as waterproof to -1m. I have no experience with this light, but it seems like a good light. This light is regulated. It only gives one hour of regulated light on high, but up to 24 hours of regulated light on low. After the regulated time expires, the light continues to produce usable light. There is an indicator light that signals when batteries are low. There is a review at:
http://www.flashlightreviews.com/reviews/pt_quad.htm
Then there is the Tika Plus, available for arround $35. It is a good light. I have had mine for years and it still works well. It is a little tempermental. Sometimes when it gets wet, it works fine. Other times it dies when wet. It has always recovered after drying out. It has a very long runtime, but it is not regulated so the light quality diminishes. There is a review online at;
http://www.flashlightreviews.com/review ... t_plus.htm
The regulated PT lights can use alkaline, lithium, or rechargable batteries. I have used rechargeables in my Tikka+, but it is not reccomended and when fully charged, the rechargable batteries cause the light to flicker. The ability to use rechargeable batteries may be a big plus in your situation.
From what I have heard, PT has a great warranty. I have never had to test it. If PT is giving you a deal through their educational program, I would go with them. If I had the choice, I think I would pick the EOS.