100 gig hd + 2 512 ddr2?

I know I am pushing it fast but I like speed.
I bought the m65-s809 Toshiba it has 1 stick of 512 533mhz ddr2 200 pin memory and a 100g hd 5400 rpm.
I am looking at the seagate momentum 7200.1 100 gig hd 7200 rpm 8mb cach and I will have my 2 new sticks of 512m 533mhz 4200 ddr2 memory tomorrow.
Will these 2 items make this thing fast as well as stable, Or shoud I look to upgrading to a 760 m pentium processor also?
Of these 3 things in what order will I see the greatest gains in speed.

 

It will be faster, but not like twice as fast. You should note, upgrading your CPU will void your warranty. I'd do the hard drive and memory first.

 

What is your current processor? All Pentium M's are pretty speedy, so I don't think you're going to see as much of an increase in speed as you'd like. What zazonz said is something to take into consideration - you will void your warranty if you attempt the CPU upgrade.

If you upgrade the HDD and RAM you'll get much more of a speed boost than if you did the processor.

 

Are the seagate hd's pretty good?
They come with a 5yr warranty, I assume that means the are pretty reliable or it's a really bad warranty with good marketing and a ton of fine print.

 

I would prefer Hitachi since they have been making them for a few years whereas the Seagates are still fairly new.