After reading through this thread I have noticed a couple things. First, given the OP's application (flashing a
logo when a goal is scored) there is no way this can be done with a discharge lamp/CDM
Source four. Unless you have a controllable
shutter assembly the lamp just takes too long to warm up.
For something like this an old used 575W
watt moving light would be great, but probably out of the budget.
I have to second the suggestion of just getting one of the tall Little Giant ladders. While they are far from my favorite, you can get them in heights that will get you to 20' and they will be stable on the ice. You will probably need to put some padding on the feet so they don't freeze to the ice, but it would besafe and stable. Then you don't have to wait for the lift to be available.
It looks like people have given lots of information about hoists, but making that happen (safely) is probably far beyond your budget.
LED units are great, but they are very new andexpensive and right now no one has a good way to compare the brightness of them except by what you see in a side-by-side demo. Also,
LED would require some kind of controller, if you don't already have one, this is more expense.
Just my thoughts.