I'm looking at a ATI Sunpower 60" fixture, it is a used 8 bulb unit. Many ballasts will handle any combination of pairs of bulbs. For example if I wanted to use only 4 bulbs; 2 on one ballast and 2 on the other would this fixture accept that? or does it need to be run as a 8 bulb fixture? (2+6). Also, if you're familiar with the fixture I assume the wiring will dictate acceptable pairing e.g. only specific bulbs can be removed which would limit spacing options? Thx