Im not really sure, i cant use loops in good conscience. make your own, really. if its a pain, or youre just lazy, chop up some funk breaks for a nice groove, and layer some kick/snare on top of it.
loops will hinder your progression. Lets say you find 2 nice loops in a pack of 20. . . . thats 1 or 2 tracks.. . . .then what? youre on the hunt again, looking for solid drum loops that bash. all that time looking for loops could be better spent learning to layer and create your own grooves.
I have seen dnb construction kits but there is just no point. Not if you want to actually get anywhere in this scene anyway. You would be making pretty much the same tune as some other guy who bought the same pack...
Stick to buying sample packs such as the one you said. I myself sometimes use the loops with pads and stuff in, but never anything like leads and basses, as those are the elements that really shape your tune and make it stand out.
Goldbaby do a great pack called Urban Cookbook, has some quality drums & percussion samples. You have BHK which produce fairly decent drum and bass packs too.
Whatever you do, don't buy the construction kit packs, would be as inventive/creative as totally copying a popular tune.
I don't like using loops. It limits your creativity of your drums, and you can't add effects your snares, kicks, hats, etc. separately.
But if you really want to use loops, I recommend Danny Byrd DnB class, or David Carboon Masterclass.