Hi Aaron. As Marc points out, the 950/990 feature a connector for an external SB-series strobe, but can be adapted with some jury-rigging for use with any strobe that connects via a PC outlet (ie studio strobes). See:
http://www.nikon-euro.com/nikoneuro_...e900_en_12.htm
For more information.
Whether exposures from your film cameras and a camera like the 990 are a good match will be easy enough to test, simply by bracketing exposures on both film and digital, then comparing frame for frame after the fact.
And the G1 definitely makes this easier by including a hot shoe as Marc mentions.
Rob Galbraith