Cycle Finished

yipee my fishless cycle has finished 
boooo cant get to a shop till satarday   

iam thinking a few kissing gourami to start with as there on my list i want and in stock at my lfs althow i have yet to make a trip to my local maidenhead aquatics so maybe there first and then choose.
just one quick question in the flishless cycle thread it says  just before buying fish to do a big water change should this be as much water as i can get out or around about 75 percent of my tank ?

my tank is just over 150cm long and 45 cm wide  measures at about 155 cm by 48 cm once removed the thickness of the glass and holds roughly 255 litres of water with all the substrate in and decorations , and i have two external filters running in the tank so i guess this is classed as over sized filtration

yes i must admit i have found lots of conflicting information from shops saying one thing when the community creator says the opposite but i take what the shops say now with a pinch of salt , althow i must admit my local fish shop has just impressed me alot, i just telephoned him to make sure he still had the gourami in stock and on the phone the first thing he asked was the size of my tank and also weather it was cycled or not and offered to test my water if i bought a sample with me when i go to purchase

hehe ok i will take pics the weekend once there in and calmed down