All SRC assessors.
If you are buying simulator radio's I would suggest you check that the modifcations are official modifications from the maker of the unit.
If not you could have problems if you ever need to get the radio's repaired.
Solent:- is one power supply enough?
this would mean you would need 15ft of DC running to each radio or a short lead and then a 30ft length?
IMHO a "heavey duty" PSU is a tad over the top, the radio's should be drawing hardly any current if they are working correctly as simulators.
Just in case anyone is interested the Icom M421 simulators are £329 inc VAT, inc delivery, inc 20M of co-ax and inc 2 x switch mode PSU.
They still carry the Icom optional 3 year warranty.
The units are modified in house by us and we sell them direct to RYA Schools and or instructors.