You can buy the handset via ebairsoft as an H-250 handset that comes with different connectors for different style radios (
Element H-250) I had one of these before I changed radio types - this thing is effing LOUD, I had to leave my motorola on 1/3 volume and had this thing hanging on the D ring to my vest at shoulder level and I heard everything perfectly. The price is right for that unit, and it's damn near indestructible. I fell on mine, rolled on it, ran it through tangly brush..all with only the plastic clip on the back holding it on and it took abuse and kept asking for more.
I made the mistake of turning it all the way up, and had it to my ear when someone keyed up - I was fuggin deaf for 5 minutes in that ear, no lie.
As for the radio body - I'm with Gunny and suggest you build your own with either a motorola or similar radio inside of it. The shell would be relatively simple to build,(probably as an ammo box as a starter?) the dimensions of the case via google being 4x11x14 high - so what, a cut down
81mm mortar box as a base? (14.5x5.5x22.5) Thats damn close.. Just a little thicker in the can lol
A little creativity and ingenuity and you'd have it it no time I'm sure.
Worse comes to worse - you could have a sheet metal place or an HVAC place cut some sheet for you and brake it into the proper sizes. Whenever I need to build a boxy-type item, I just go to the local heating and air place here in town and they have all the sheet stock sizes I could ever need - and its cheap.
Just some helpful input from an occasional kludger
Edit - I see ebairsoft's product listing is 'in soon' so I found other links to the Element H250:
http://www.massive.hk/eshop/index.php?m ... cts_id=631
http://www.gunnerairsoft.com/catalog/pr ... ts_id=1824
(2 brands of H-250)
http://www.rsov.com/index.php?target=pr ... 50&x=0&y=0