Go for it! 
I guess I was too dumb to know how brilliant I was being. 
This seems to be the best option I can find in a pre-made solution. Almost perfect size for the body I have, good focal length, only costs half the earth... I know I can get it in a couple of days, being local to me. Not sure what impact the small hole in the center would have, but I could patch that with some reflective material.
Of course, the other solution is to make something.... after a bit more searching, I came across this site, which made understanding the parabola easier for me.
I'm also planning to make a few cardboard parabola cut-outs that I can take to the dollar-store, in the hope that they may have a dish/bowl that just happens to have a parabolic contour.
That Edmund Optics mirror looks so perfect! Have fun trying to find/make something. Hope it goes well for you. I’m looking forward to seeing your finished product!
That 40.5cm mirror I linked earlier is still at one bid $9USD and has 14 hours left to go. It will probably end up well below the $62 price of that Edmund Optics mirror. If nobody else bids on it, somebody’s gonna get it for $9USD. It can ship to Australia, and shipping is free. 
That mirror looks great, but too long a focal length, & a little too large. Also, I don't think they are going to ship for 'free' somehow :)
There's quite a few places selling it, & the cheapest I could get one for is around $145.
Maybe for a long focal length like that, you could use a microwave dish. It seems the main problem would be getting it smooth and shiny. A simple way might be to cover it with aluminum foil.
I spent a little time yesterday making a parabolic cut-out. I'll take it with me to the shops today, on the chance that I find a bowl or something with the same contour.
And a question for the driver gurus;
If I were to piggyback 3 or 4 FET's on the same board, will the 13a have a strong enough drive signal to operate them all?
With a nice high gate voltage a good FET can run up to 100A.
Little bit of progress yesterday in post #1.
Actually, It may have been a step backwards.... :~
& a small step forward today in post #2.
Sorry to hear about the set back, but it's great to see you have a sense of humor about it with "Jack" and all.
At least the write-up is already excellent, great reading, that will impress the judges as well :-) , I hope that the mirror will work out in the end. Keep going!!!
Light engine is looking great and so it your write up and pics. :)
Jacks a good looking assistant but he appears to goof of as much as my two assistants. I bet if the three of them got together there'd be a bunch of trouble. Its good to see some progress on the light.
That shallow, long focal length Edmond Scientific reflector looks like it should be used in a retro configuration. The light sources they used in WWII search lights emitted in all directions.
What about using your template to make a clay negative and forming the plaster over that
Yep, been there, done that yesterday.
See end of post #1 for latest update.
While I was researching making parabolas, I came across the term 'spinning' a few times.
As it turns out, a liquid that is spun at a constant speed in a container forms a parabola on it's surface. The faster the rotation, the shorter the focal point.
This is what I'll be trying next, by using a low viscosity epoxy, or plaster mix.
The key seems to be keeping a consistent speed, whilst the solution sets.
This is going to produce some serous lumens.
Others of my group did that when I was in Germany, to use as a light gathering mirror. I think we used polyester. It should start as a liquid and not change volume too much when it hardens. I don’t recall how we silvered the surface. Evaporating aluminum on it in a vacuum probably gives the vest shine, but without a vacuum one could stick aluminum foil to the surface.