Advice desperately needed first family car

[pxmx]

So we need to buy a new car as my current car has suffered enough!!
We live in Ireland, out in the wilds & the roads are appalling. I do around 20k miles a year so I defiantly want a diesel, 1.7 tops as above that the tax is extortion. We are trying so I want something with a descent sized boot as we plan (fingers & toes crossed) on two kids.
I'm blue in the face from looking so I'm here hoping for some advice The car will be bought in UK & the budget is 6k. I'm open to any suggestions just want something solid, diesel & with a mammy sized boot!!

Skoda Octavia estate has a massive boot, I reckon I could sleep in mine! Does about 600 or so miles on a tank of diesel, not sure about engine size though, might be a 1.9

Thanks Mygast, I'll check out the engine sizes, seems great on diesel!! I can't wait my car now is petrol & I swear I need my own pump at this stage