Hard Drive (maybe memory) upgrade for XPS M140

So I have a Dell XPS M140 that's hard drive is failing. I checked the Dell website and they offer this hard drive for my laptop:

http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=341-2209

I figured since I have to get a new hard drive I might as well upgrade. I looked around Newegg and found this hard drive:

http://www.newegg.com/Product/Product.aspx?Item=N82E16822136130

It's cheaper and has 40 more gigs of space. My fear though is that it won't fit or work properly. Both have the same form factor of 2.5" and both are ATA-6 interface. So is there anything else I should be worried about or take into consideration? Do you guys think it'll work?

For just $20 I could get this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16822146047

It's more expensive then the Dell offered hard drive but is ultimately a better deal because of its speed. Would there be any problems with this hard drive?

Since I'm upgrading, I figured I might as well upgrade my memory too. Dell offers this for my laptop:

http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=A0743799

Again checking at Newegg I found this:

http://www.newegg.com/Product/Product.aspx?Item=N82E16820220078

It's cheaper and as far as I know a good brand. But I've heard horror stories about memory upgrades so, again, I'm apprehensive. Do you guys think it'll work in my system? Are there other memory choices you'd guys recommend?

On a related note, if I go through Newegg's memory picker for your system form it recommends PC2 4200 for ram but Dell seems to recommend PC2 5300 (that's the only speed they offer). Any difference I should worry about between 4200 and 5300?

Sorry for the very long post. Yeah, I'm sure I'm just being paranoid but I'm not used to upgrading computers.

 

Is there anyone out there that can help me?

 

I would not buy upgrades from Dell because places like NewEgg have better prices.
Yes The HDD's you found should work fine.
The RAM you found should work fine, the important is the type (DDR2) the module (200pin SO-DIMM) speed does not matter so much between PC4200 and PC5300 as both should work. But I would get PC5300 if supported running at 667MHz, I personally would get PC4200 if 533MHz is all that is supported even though both should work either way.

 

Thanks for the reply powerpack.