yeah, you might be better going for a midweek slot to begin with, until you have that night running on a regular basis. obviously, there are far more vacant venues during the working week, and a club owner would feel more at ease with putting you on during midweek, because they want people through the doors on fri and sat, and i guess some places wont take a gamble. that coupled with the fact that its very rare a venue becomes availible on fri/sat (that is assuming its the first night you've put on?)

why not try the think tank? (although i think that is fully booked on every fri/sat of the month) i hear that if you get 250 people through the door you dont have to pay a penny. and the most you could end up paying is £250, i think the policy there is for every 50 peeps you get through the door 50 quid gets knocked off the price.