The best night to go is Saturday night. No matter what time of the year that night is always busy if not packed. All other nights are iffy off-season....some Fridays for instance are really busy and some are kind of empty.
Looks like you'll be in town on two Saturday nights. If you're only buying the 1-club ticket, why not do one Saturday night at Mannequins and the other at 8TRAX which is also a lot of fun. The single club ticket is around $10 while the all club ticket is around $21. For the latter, you can pay $5 more and the ticket becomes valid for an additional 5 consecutive nights beyond the first night.
BobK/Orlando