Hi Erin
I'm no expert but I do have a few views on buying PCs - and I tend to use them for much the same as you - I'm not into games, music or downloading videos etc
The technology is always on the go - both hardware & software - will be obsolete in 4 years +/- a couple. I got rid of my old pc and replaced with a lap top about 3 years ago because - it didn't have a CD or DVD read or write - it didn't have USB ports - everything uses them now. It used windows 98 - great and stable but sadly no longer supported.
If you wait for the next level of hardware/software you will never buy - there is always something new. For software I prefer to use slightly out of date OS - usually more reliable (only my opinion - my nephew who works for microsoft disagrees ABSOLUTELY with my views).
I don't understand the CPU speeds given - I think I have a celeron - it was quoted as 1.7 whatevers and is more than fast enough for me. Most machines come with 256 basic memory - buy 512 - much better for speed and for being able to have multiple windows open without hassles.
Assume that you will buy again in about 4 years, so look at what you want to spend for that time frame. I bought a Dell Laptop - 3 years ago cost me $AU2000, the same today is $AU1000. I find the lap easy to use, compact, takes up less room on my desk and I can take it away when going ancestor searching. Mine has 30gig disk (quite small by current standards) but I have used only about half. I do have an external 40gig disk (USB attached) that I use for backup. Backup to CDs is tedious.
If you don't like the lap top keyboard/screen you can attach larger ones - I see no need for this but it's a personal choice. I do use a separate USB mouse.
About the only other thing I would add- get at least 4 USB ports - I only have 2 and am eternally swapping things. One gets used for the mouse, so I only have 1 left for all other options - scanner, printer, camera, back up disk.
(1 pound is approx $AU2.5)
Trish