Here is a list of cable compatible boxes if you mix and match tuners im sure there are more out there these are ones known to work so far
Q5 HD PVR
Openbox C4
Amiko Mini HD
Amiko Mini Combo
Cloud iBox 3
Estar 800HD SE
Estar 800HD SE Triple
Sunray 800HD SR3
Sunray 800HD SE SR4
Blade Combo
DM800c
VU+ Uno
VU+ Ultimo
VU+ Duo 2
Gigablue SE
Gigablue SE+
Gigablue UE
Gigablue UE+
Gigablue Quad
Gigablue Quad+