Having worked with a few DnB producers over the years - in my experience - where you get it mastered is the absolute least of your worries. Someone who makes authentic DnB, say Dj Krust, could get his material mastered by the classical guy @ Abbey Rd and it would still set the floors at the DnB clubs alight.
The biggest concern I would have is that of making the DnB 'authentic', i.e. so it doesn't sound like DnB made by someone who's from a Pop or Techno background - this is easier said than done.
Someone who's really into DnB culture, if they're articulate, and even if they're highly non-technical, will be able to instruct the engineers they work with as to what kind of sound they should be aiming for, playing examples if necessary.
In my experience, the biggest issue will be how well this person can articulate what they want.
Your biggest worry is that which I highlighted earlier IMHO - you want 'authentic DnB' - NOT an inaccurate impersonation of DnB.
I do not believe that anyone who is not fully immersed in DnB culture, i.e. frequents the clubs and listens to the radio shows fanatically, is likely to make 'authentic' DnB - it might be interesting music in its own right, but authentic it won't be.
There are a lot of tricks known to the DnB producer. Unless you have someone kind enough to show you them, you'll need a lot of dedication to work them out for yourself.
Not trying to pour water on anyone's fire here - but understand that, if you do not live and breath DnB, the chances are that you won't make authentic DnB. There are exceptions, i.e. the 'chameleons', who are able to get into the mindset of any genre, but these people are rare and often very successful / expensive.
8-bit and 12-bit sampling is your friend. Sherman filterbanks are also handy for DnB. Don't view the production process at DNA level too much - it can pay to deliberately look at the bigger picture and employ a rough-and-ready approach. Being anally retentive with a drum grid rarely makes good DnB - you'd be better off sampling all the drums as loops and playing around with start / end / general triggering / on-beat / off-beat etc.
Justin