Hi ToadWales & welcome to the forums.
All those XPS 8100 PCs (click here) will be far greater than your needs.
Consider going for a lower & cheaper spec & add a graphics card separately. These are also a bit overkill for your usage, but will save you a bundle.
A GT 240 graphics card should do nicely click here. Or even a HD4670 click here.
If you need a monitor, these can be purchased separately, as Dell's upgrades tend to be overpriced. G