Yes,
cyc fixtures are ideal due to their asymetrical
reflector design providing a significantly more even
wash from top to bottom than other types of fixtures. Of note, though, is that different models of
cyc fixtures require different
spacing from the
cyc and from each other dependent upon the height of your
cyc and the brightness you want. For example, the
Altman Spectra
CYC 100
LED cyc lights my theater are effective at evenly lighting our 16'
cyc from a distance of 4' away and 5'-6" away from each other in order to get the
intensity we need. If you can't get your instruments further away from the
cyc, you'll need more of them in order to evenly light the
cyc left to right.
Now,
downstage or upstage actually depends on the type of
cyc you have. If you have a
leno filled
scrim, attempting to light from upstage will not work. It can work with
muslin, natural or synthetic, but
downstage is definitely going to be punchier. Some theaters also use cycs made from front and/or rear projection material. With a front/rear material you can light from either side as necessary, but with a rear projection material you really should light from upstage.