Hi Wes,
I have no idea on who sells Detech in the US,
On the 7000 / 5000. A part of the reason the 7000 gets more deeper small gold is the coil. You have to realise that the 7000 coil has three coils inside, the transmit coil is very small and puts a lot of concentrated energy straight down onto the small gold. If you do the side by side comparison with a 14” mono it is not fair, the correct way to do side by side is to use a 11” DD or a 5”x 10” mono. In the US as far as i know, the coil is not so hot and mineralised thus I cannot see why the 7000 would get more gold so it must be a coil winding size mismatch.
The 5000 can have its gain increased by a few component changes and changing the timing using the modified manual tuning can make the 5000 super sensitive to very tiny gold.