"hold" note uninterrupted feature

[Sorceror777@aol.com]

Im looking for a unit that will allow me to play one note, hit a button on 
the floor once, and it will sample and hold that note continuously and 
uninterrupted without any hint of decay or repeated attacks. Something 
like a 
digital sustain pedal (for a guitar rig), that does not repeat the initial 
attack like a looper does, but will hold a continuous drone of the note I 
play when I activate the unit. 

Also I do not want to have to hold the pedal down to keep the note 
sounding, 
I want to be able to hit the button once, which makes the note sound 
uninterrupted for as long as I want, play whatever I want unaffected 
(echo-free), and then when Im sick of the background droning note, I hit 
the 
button once again to deactivate the unit. 

The unit may be a simple stompbox or a rackmount, as long as I can control 
the feature via footswitch.

Anyone know of ANYTHING of this sort,
thanks
Jesse Malone