I was thinking that the fuel consumption would play a part, and doing 18k a year, I don't blame you. But I'd seriously consider an automatic, they may be rare with a diesel but there are some out there.
I had the use of a 9-3 saloon, 1.9 TiD, 150 bhp, for a day recently. Six speed manual box. Very fast, but I was constantly grabbing to change gear. The power was all in a very narrow band and it would have driven me mad if I had it as my own car. Never mind the high 40s mpg. IMVHO it would be great with an auto box, even losing a few ems per gee. (and that's my view of every diesel I've driven, with both types of box, whatever the make.)
There are a couple of dozen 1.9 auto estates on autotrader.