I don't think the ex25 will work with the 14-42. Short focal lengths and tubes don't work well together - in fact, I'd be surprised if it is possible to focus under 40mm.

The 14-54 is a good lens (I had one), but it's no macro lens. If you're serious about macro at all, the ZD50 or the sigma 105 are better choices. The 14-54 is sharp and will focus close, but it just doesn't have the magnification necessary for macro work.

If you're still on a shoestring budget, get the 40-150 and the ex25. It's cheap and is reasonably sharp. I use the 50-200 with the ex25 more than any other lens and tube combo, although it's also useful with the zd50 for real macro magnification.