Some final configuration questions for R61

So, I have pretty much decided that I'm going to be ordering the R61,
these are specs I've got right now:

Processor: Intel Core 2 Duo processor T9300 (2.5GHz 800MHz 6MBL2)
Operating system: Genuine Windows XP Professional
Operating system Language: Genuine Windows XP Professional - English
Display type: 14.1 WXGA+ TFT
System graphics: NVIDIA Quadro NVS 140M 128MB
IEEE 1394: IEEE 1394
Total memory: 3 GB PC2-5300 DDR2 (2 DIMM)
Keyboard Language: US English Keyboard
Pointing device: UltraNav (TrackPoint and TouchPad)
Hard drive: 160GB Hard Disk Drive, 7200rpm
System expansion slots: PC Card & Media Card Slots
WiFi wireless LAN adapters: Intel Wireless WiFi Link 4965AGN (US/CAN/LA/AP)
Bluetooth: Integrated Bluetooth PAN
Battery: 6 cell Li-Ion Battery
Power cord: 90W AC Adapter; NA, LA, (2pin)
Publication Language: English US Publication for XP
Integrated wireless antenna: WLAN a/b/g/n antenna


But first, a few things I'm not sure about, first, the ram, is 3gb necessary for XP? I've heard that 4gb is, I just don't want to buy it and never fully use it.
Second, the hard drive size, the reason I picked the 160gb is because its at 7200rpm, and for some reason, for the 7200rpm speeds, it jumps from 100gb to 160gb, and you can only get 120 at 5400rpm. I mean, I've heard that there's noticeably difference in speed between 5400 and 7200, so I guess it's worth it?
But most importantly, for those in Canada, you might be able to help me out, what is the main differences between
2 Year EasyServ + 2 Year ThinkPad Protection for 1 Year EasyServ ThinkPad
and
2 Year Onsite 9x5 Next Business Day + 2 Year ThinkPad Protection for 1 Year EasyServ ThinkPad ?

Any warranty suggestions and suggestions on ram and hd size would be awesome (I would not trust myself installing more ram after purchase)

 

looks solid. keep the 7200 rpm. warranty is up to you. i always go with at least two years. i wouldnt change a thing.

 

Most people in my experience don't need 3GB of memory unless you have a particular use that requires it. XP even runs well with 1GB.

A 7200RPM drive does give a performance uptick. Some of the bigger 5400RPM drive offer very good performance, but access time are a little slower.

I usually get the one year warranty, but pay with my AE card which adds an additional year of warranty to the machine. Some CC companies offer this. You might want to look at the warranty guide.