Tell me you've been here already?
Logic x is absolutely enough, don't feel you have to spend more money as that's not the case. So many d&b producers (the top level ones - Spectrasoul, Rockwell, Wilkinson, TC, DC Breaks, etc etc) achieve great things with logic, and the build in plug ins will serve you well.
The number of d&b tunes with a sub bass from EXS24 (the default patch) is huge.
So what about loops? Well Hi Hat loops are fine, shaker loops are fine, musical loops are fine (baseline, melody etc) but I'd probably stay away from a full drum loop, and use individual hits instead.
You can get a lot of good stuff for free - check out Loopmasters, they do free tasters for their sample packs, and have some really good ones for drum and bass. Find a drum loop you like and chop out the kick and snare to use.
Also find as many remix competitions as you can and download the stems.
The sound of D&B has changed a lot over the years, and is moving away from break beats. A more modern, synthesised kick just hits a lot harder, like wise snares.
Achieving a good sound when producing drum and bass is all about starting with the right sounds. You're much better off spending half an hour finding the right sample than half an hour EQing the wrong sample.
Use 1 good kick sample, 1 good snare (you'll get into layering as your skills progress) and you can fill in the space between the kick and snare with chopped up breaks, hi hats, rides, bongos, congas etc!
I found the Youtube tutorials really helpful.
The Sub Focus ones for Computer Music are pure gold - he explains what to look for when choosing samples.
If you feel like spending money, Addictive Drums is really good.
DLR has a great video on it.
Keep at it, it won't happen over night and Drum and Bass is one of the hardest genres to produce well, but once you finally "get it" it's hugely rewarding.