I don`t find the LD stuff that bad and I use a lot of it with a local P.A firm.
They are cheap and cheerful and in my opinion will work fine if you carry them carefully in a decent box.
Regarding hooking it up, you can choose whether to send a full mix from an aux output on your mixer, OR,if as you said, you just want your own vocal in ther, you can use an XLR splitter cable (Y cable 1xfemale to 2x male) [url="http://www.ebay.co.uk/itm/1-Metre-XLR-Mic-Splitter-Cable-Lead-Van-Damme-Cable-/120681436896?pt=UK_Computing_CablesConnectors_RL&hash=item1c192c96e0#ht_664wt_932"]http://www.ebay.co.u...e0#ht_664wt_932[/url]
Use the cable to split your vocal mic cable into the mixer as normal, and then the other connector into the mono input on the LD transmitter.
Use the input gain on the transmitter to set the level into the box, and then use the volume on the receiver for how loud you want it in your ear.
That`ll work, but you wont have any eq on your mic.
OR if you have direct outputs on the channels on your mixer, you can take the vox signal from there,(but the cheaper mixers don`t tend to feature direct outs), and even from the insert point as well, but you may have to make or buy a special cable for that.
The way I do it with a powered mixer with no spare auxes, is use the split cable to go into another smaller desk, like a spirit notepad or behringer micro desk. Basically any portable mini mixer with a couple of chans and a bit of EQ etc, and then send the mix out of that into your IEM transmitter inputs. Then you can get a bit of tone and level control.
If you decide later that you want a bit of bass or kik as well etc, you can Y split them into your mini mixer too.
If you aren`t clear about any of this, ask away and I`ll do my best to explain it better.
Or I can rig mine up and take a few pics if you like.
MM
p.s the frequencies on the LD pack are licensed and free to use already, so no prob for the future just yet.