Thanks for the great responses guys    
 
Unfortunately in these hard times a fretless is out of the question (Unless I get ruthless with the sandpaper  ), though it would be nice to have one. 
Using my thumb has improved the sound no end, thanks iamthewalrus.  
Bilbo , I was trying to pluck, almost like d bass technique but playing softer and turning up the volume has helped. 
 
I'll try a set of nylon rotosounds to see how they stand up to the rest of the set. Although at the moment I've only got the 1 bass so I'm trying to get the best of both worlds, as I play the Sax and guitar too makes my musical wish list long and expensive!.  
 
I have seen the ashbory basses, not a bad price but I've no idea what they're like and 300 quid is a little too much to experiment with.  
 
Thanks again for the advice  
 
Steely