I'd like it to be comparable on average in pace to my DF bike, on moderately rolling terrain, I've read about uphill performance.
That's achievable, with an emphasis on 'average': you'll waste energy if you try to match pace with DF solo bikes.
Uphill performance is, as usual, mostly about power vs weight. The main reason people think recumbents are slow uphill is that they tend to be heavy (the vast majority you see in the wild are n=1 tourers), and they go faster on the flat (making a weaker rider appear faster by DF standards). There is a loss of biomechanical efficiency, but it's usually secondary to those effects.
Audax plus possibility of light tours as well, able to fit in back of large estate or fit on bike rack designed for my DF bike. Fun to ride however that might to be defined.
Plenty of bikes in the 'light tour' bracket, anyway. Fun to ride is hard to define; they're obviously all way more fun than a DF bike, but differences are subjective.
I'm more of a spinner uphill and lover of descents.
This is undoubtedly a good thing.
Such a wide range of recumbents , I'd be considering 2 wheel variants. Any advice on where to start?
Visit D-Tek (other recumbent dealers are available) and play with as much as you can. Well worth trying heavier tourers, trikes and other things you don't really want, if only to get a feel for the differences. Particularly the different handlebar and seat styles.
Buy something you can get a good deal on (so probably second hand), expect to replace it with something else in a year or so when you have a better idea what you actually want. It's a truism that the bikes that newbies tend to get on with stability/control wise aren't necessarily the best for performance.
'Bent legs' take a few months to develop. Probably takes a similar amount of time to get a decent level of confidence at controlling a recumbent bike, though a few hours spent practising manoeuvres in a park or industrial estate is well worth it.