The Trinity and Q Rack are two awesome pieces of kit for sure. You should have no problems producing DnB, trance, etc.
What you call the REM1x I think is actually the Rm1x by yamaha? The Rm1x is a great sequencer. Actually it is one the best if not the best hardware sequencer on the market right now. It's especially great if you are doing live performances. It's soundset leaves much to be desired though in my opinion. With the Trinity and Q you shouldn't need to go to the RM1x for too many sounds anyway. Do you need the Rm1x was your question and the answer is no. You could always sequence from your computer using Cubase, Logic, Sonar, etc. Keep in mind that you have a 16 track sequencer built right in to your Trinty that is more than capable. In the end the desicion is yours based on your needs.
As for the soundcard, keep in mind that the Luna2 only has a pair of analog ins and a pair of SPDIF ins. You could opt to buy the additional breakout box which would give you 8 additional analog I/Os. If you don't buy the breakout box you will then need a mixer. If you do buy the breakout box Luna's software mixer will be more than sufficiant. Keep in mind what your goals are here. Do you plan on doing any live work/gigs? If so you will want to invest in at least a modest hardware mixer. If you are just starting out I would go with the Luna2 coupled with the breakout box and just use the Luna mixer (which is really cool).
Here is the link to the Luna2 breakout box:
http://www.creamware.de/en/Products/...ox/default.asp
Good luck with whatever you choose
peace,
fitz