Which used Mazda 6 estate should I buy?
The smallest petrol engine in the estate is a 128bhp 2.0, and it's capable enough, but not the best choice. Instead, try to find one of the two 2.0 diesels, with either 119bhp or 140bhp, which have just the kind of strong low-rev pull that you need in a hard-working estate. Preferably, go for the 140bhp version because, besides its extra power, it also covers a few more miles per gallon.
Whatever engine you go for, you'll find plenty of equipment. Even the cheapest S models have standard air-con and a CD player.