Hi Felix, nice album to be converted by. The Aura was my favourite album of 2011!
I've switched to fretless bass about 2 1/2 years ago and basically never looked back. Back then I faced the same task as you and just recently faced it again. Finding the right fretless bass for yourself is not easy, especially for metal, you pretty much need to find out yourself what works for you. But at the same time, this gives you more space to find your own voice...
There are much less options to choose from than on fretted basses (except when going custom of course!), WAY less instruments to try out in person, and you can pretty much all forget about getting a special color/finish on a production bass. The target audience for fretless basses is small, so companies seem to usually just produce them all in natural finish. Except the cheap ones and a few exceptions from the rule.
For a nice selection of fretless basses with at least a few of them in your price range, check out Session Music in Frankfurt (ehemals Musik Schmidt
).
http://www.musik-schmidt.de/de/Baesse/Fretless-Baesse
For example they have some of the Warwick Rockbasses and a real Corvette priced at 1099.
I went there two months ago because I needed a new fretless bass better suited to my tonal needs for recording my bands debut album. Long trip down from Hamburg, but well worth it, because their staff is very knowledgable and helpful!
They also put demo videos of alot of their basses on Youtube, so you can get an impression of quite a few models, like this Sandberg Panther:
I have read good things about the Yamaha TRB5 Fretless which Stef recommended, this should be a solid choice. I think they aren't made anymore, but if you find one used it should be in your price range.
Speaking of used, definitely keep an eye on the bassmarkt if you're thinking about buying used:
http://www.bassmarkt.de/?q=fretless
For example there's a Gary Willis for 450 that just went up 4 days ago.
Personally, I am a fan of ebony fretboards and two-pickup configurations.
Since the fretboard will wear down from usage, you get more mileage out of an ebony fretboard and a slightly snappier sound compared to a rosewood fretboard.
While the bridge pickup on a fretless produces the well-known mid-heavy "MWAH" sound best, a neck pickup with the right EQ can get closer to the sound of an upright bass (not like the real deal, of course).
The combination of both pickups, if wired in series, gets you closer to the typical scooped sound of a fretted bass.
Ok, that's all I can think of right now... any questions, just ask!
Good luck and have fun on your quest, I promise you won't regret it! There's a certain freedom and expressiveness in the fretless world which you just can't get on a fretted instrument.