I've had both axxis ultimates (currently dealing with them now) and hawk HPS's.
Get the hawk HPS's. You will like them. They may squeak a lot if you don't use enough anti-squeal glue on the back of the pads where they contact the caliper. (And let the glue dry at least 12 hours before you bed in the brakes or heat up the brakes in any way, otherwise it significantly looses it's effectiveness.)
If you have the money for extra brake accessories like SS lines or brass caliper bushings, go for it. Either way, if you do anything other than just change pads, go ahead and do a full brake fluid flush. Super blue racing fluid works great. (It's not limited to racing, so don't get the wrong idea. It's just high preformance fluid called racing fluid.)
When it comes to spending money on a car, you can never spend enough money on devices to help it stop and other saftey equipment. Sure, mashing the gas and going really fast is loads of fun, but it wont be any fun at all if you can't stop the car!