I would go for something like this click here / click here for £349 / £369 (£20 difference is for double the hard drive space in the latter). Similar AMD system for £379 click here.
And add a dedicated graphics card like a HD4350 for £25-30 click here.
Card reader, keyboard & mouse included in all the above. Monitor can be purchased separately as Dell's upgrades are a bit overpriced.
One thing to be aware of with the above systems is that all of them come with a 64-bit OS (Win7). Some of your older software/hardware may be affected by this. Related discussion in this recent PCA thread click here. G