Just for information i decided to go with a Dell XPS M1530 with the following spec:

Intel Dual Core 2 Duo T7250 @ 2.0ghz

2048gb ram (gonna up it to 4gb in the next couple of weeks)

250 gb 5,400rpm hdd (im going to upgrade to 120 7,200rpm soon)

Its running Vista Home Premium but im considering downgrading to XP Pro as it feels a little sluggish.

Matt.