As far as the multiple patterns goes, if you were to go down the transfer/resin/PE route I don't think it'd be necessary to instantly replicate all the variations - you could get away with one type for each vehicle you wish to apply it to (at least initially, if the interest was there) - so you'd have one type for PzIII's, one for IV's etc as you'd have to produce sets for each vehicle individually anyway.
Here's a (reasonably comprehensive) list of vehicles by pattern & as you can see, there's a lot of cross-overs:
Vertical columns of horizontal ridges
Pz III
PzIV H & J
Pz.Bef.Wg IV
StuG III
StuG IV
Jagdpanzer IV (all three variants)
Sturmpanzer IV
Flakpanzer IV (both Wirblewind & Ostwind)
Panther Ausf A & G
Tiger I & II
Jagdtiger
Horizontal columns of vertical ridges
StuG III Ausf G
Pz IV Ausf H
Panther Ausf G
Horizontal columns of vertical ridges with one-way diagonal grooves
Panther Ausf G
Horizontal columns of vertical ridges with vertical grooves separating the coulmns int small boxes
StuG III
StuG IV
Panther Ausf A & G
Small squares
StuG III
StuG IV
Jagdpanther
'Waffle' pattern (square)
StuG III Ausf G
Sturmhaubitze
Panther Ausf A
Tiger I Ausf E
horizontal columns of diagonal ridges with the diagonals changing direction for each column
Pz IV Ausf H & J
Horizontal columns of vertical ridges with diagonal grooves forming rhombuses
Panther Ausf A (G?)
Vertical columns of horizontal ridges, separating the columns into small boxes
StuG III & IV
Panther Ausf G
'Waffle' with rhombuses
StuG III & IV
Continuous vertical ridges
Panther Ausf A
(apparently a number of SdKfz 251 Ausf D's also received this pattern, though I've never seen an example)
As you can see, there is quite a lot of cross-over, but the first pattern covers nearly everything so if you were going to to Zim, doing that one would give you the greatest coverage.