Well, re-working aluminium can be risky so on the brake lever side I'd buy a pattern part - when you squeeze that lever you want to know that it's not going to break.
On the clutch side, it might be worth trying to straighten the lever.
Aluminium work hardens very quickly and needs to be annealed - often several times - to move it a long way.
There are several old methods for annealing aluminium.
The one I know is to light a match beneath the metal, allowing it to become covered in a layer of soot. Using a blow torch play evenly over the lever until it is hot enough that the soot burns off. I believe a similar gauge can be had by rubbing a bar of old soap over the metal.
Once you've done this the metal should be annealed and able to be worked some way. It may well need annealing several times to move it far.
Bear in mind that most modern levers are cast, and may include faults and impurities that will cause fracturing when being worked.
If you've got access to dye penetrant inspection or X-ray kit then give it a go and let us know how you get on. Otherwise I'd just stick to the clutch lever.
On a side note, for the last 10 years I've taken to filing small (3m deep) notches in the leading edge of my brake and clutch levers, about an inch in from the ball end so that if you drop the bike the lever breaks near the tip rather than bend or break nearer the root. In the past it's proved useful, but strangely I seem to have stopped dropping bikes...
Let us know how you get on.
arrrf.
