Sure... you could use solidly-stacked bricks (with something like felt on top) or a quality, entry level stand to raise the speakers by about 50cm, but bear in mind that it won't be the most stable of arrangements, and I personally don't think there will be much point anyway.
Raising the speakers will perhaps sharpen up the treble slightly. Higher-frequency sounds are usually more directional. As a result, having the tweeters at eye level will probably bring out more HF detail than if they were on the floor; you'll get a brighter, more lively feel from the speakers and possibly a widened soundstage/better imaging. This would be good, but isn't too critical with dance music so I'm sure you'd be fine with the floorstanders just used conventionally (i.e. on the floor). Bass won't be improved noticeably at all by raising them up. In fact - from your point of view, you may notice that bass "presence" will decrease if you raise the speakers due to decoupling (depends on how you raise them though, I guess).
Perhaps get them and play with positioning/mounting systems, then you can decide whether you want to raise them or not.
MuFu.
P.S. Since these are going to be used for dance mixing, I'd be inclined to favour the Eltax too. A mate that mixes DnB for uni nights uses a pair of Millennium 500's for his "work" (lol); there isn't a £130 speaker around able to go that deep and that loud. They have a weird lift in the mid-bass which makes them sound heavier than they actually are, and they're not the most refined speaker in the world by a long, long way. They are over a metre tall and use two 25cm woofers for handling LFs, though - a lot of *boom* for your buck.