Hey Michael,
If you are sure you need two, then the NPM5s are a decent buy for the money. Although there are quite a few others in that price range. There are plenty of reviews on the blog. Just search for speakers and you should be able to find some articles.
From the specs, I would say they are gonna be a tad underpowered. With just one 5″ speaker and a 20W amp powering 2 speakers, I am not sure you are gonna get that rich bass experience you would probably be looking for. You could augment your set with a subwoofer of course, but then you might be better off getting a 2.1 set to begin with. Don’t think Numark make a sub that matches the npm5s.
The NPM5s, like most “studio”-type monitors, aren’t really suited for anything else than sit on a shelf, although with a grill over the speaker fronts a little less vulnerable than the fully open ones (like KRK Rokit series for example).
If you only need one (I only use one and my headphone, no need for stereo really), you might want to check out the npm100. Great as a monitor for practice, but sturdy enough to take with you as a booth speaker.
Or you can check out small (active) PA speakers. You can contemplate getting a pair of used ones, just make sure you get them from a reputable source. 8″ – 10″ would be a nice size. The good thing about those is you can use ‘m when your friends start asking you to play at their parties :-). Omnitronic have one for example that is an 8″ with 80W RMS. It’s your typical entry level PA stuff, the same manufacturer that does Citronics & American DJ I think. Don’t expect wonders, but they will most definitely give you (a lot) more low end and body than the NPM5s, I am sure.
I guess it depends a bit on if you want it to sound nice or more “clubby” too.
Last but not least. If you read some more threads on speakers, there is one rule that still stands: “you get what you pay for!”.
Greetinx,
C.