literally could use anything but roland , moog and virus hardware synths seem to be quiet popular , and if you want something a little more entry level and not burn a hole in your pocket a microkorg is a good start.
you might not need a TI. The sound engine is still basically the same as in B and C, which cost a lot less. ti integrates with computer, has more polyphony and a few extra effects, but in the end you get pretty much the same bass sound from an older and cheaper one.
i dont know any hardware specially made for dnb but access virus has been industry standard for a long time along with a mackie desk and an emu e6400 sampler.
but you dont have to buy anything you can just download freeware.
get buzz (free). or u-hes ACE (possibly not free but there is something similar that was totally free, ill get back to you when i remember what it was called). their hardware equivalents cost over 1500 euro. theyre modular you see, and modular is cool as crap, with a bit of imagination and resampling you can achieve almost any sound imaginable.