From personal experiance;

Outrage
Hyperion
Thunder power
Flight power

Are all brilliant makes.

Turnigy... do the job, but there not the best...

For the price, out of the lot id suggest you go for flightpower. for your drill motor drive you could get away with quite a small pack, not sure what motor your planing on driving your disc with though? so cannot suggest a good size pack yet.

This has come up in discussion many times. The basics when using lipos are;

2mm base plate
Charge in lipo sack
Balance charge as often as possible.
Inline fuse
Use correct charging/balancing equipment.

Also i wouldnt suggest doing what Gary suggested (going for 6 fights on your lipo pack)...you should never run a lipo flat! if you do you risk damaging your pack.

I personaly take my lipo out of my robot, and balance charge it after every fight no matter how long the fight was...This is for 2 reasons;

1) to make sure its fully charged and all the cells are ok
2) so i can make a visual observation of the pack after every fight (check for damaged - chaffed wires, dodgy connections etc)

Another important rule is make sure your wiring is up to scratch...no dodgy exposed terminals etc... everything should have the correct rated cable, attached to the correct rated connections... preferably covered in heatshrink.

All of the things above will be checked on your tech check.