I suggest Sennheiser. I see the Sennheiser 122P (lavalier cardiod) on eBay for $300-400. There are also handhelds and plugon transmitters. All VERY clean, reliable, and 1028 channel options.
What camera do you want to shoe mount on---I have a PD-150 and have a mounting bracket that attaches to the bottom of the camera and arms out to the side---Makes the camera slighly unbalanced but does the job. I guess you could velcro the receiver to the handle--but thats a bit clumsy and causes me issues on hand held shots---
We use the top of the line Sennheisers, much better the 100 series, be careful as they all LOOK the same.
Down side is they are about twice the price of the 100 series but are twice as good so you do get the bang for your buck. They are designed for the receiver to mount on your belt or you can clip it to the hand strap.
For shoe mounted, I've not seen anything out there. The best in a reasonable price range is the new AT system. Sells for 799.00 with dual channel UHF receiver and comes with their new lav mic system. I've just started a review of this kit as of this morning. Impressive so far. Has Velcro, bauer mounts both.
Here's the eBay link that will search for the various "low-end" Sennheiser shoe mount wireless systems. I've been looking for a long time, hoping to find something under $300. They generally go for $350 and up.
a "low end" option (1 channel UHF) that slides into the hot-shoe is a SAMSON Airline Micro system. I have used one for about a year now and it works great. I have another multi-channel system that is a little larger... but so far I have been unable to beat the little samson unit for it's small size.
I think retail they are about $399 and that includes the micro transmitter (with Lav), xlr->mic transmitter, receiver.