Thanks for the comments. I think I'm going for about 70% for my first stocking. I'm actually looking at buying fish online as there are considerable savings to be made if you order a good number of fish at the same time, as carriage is the same for one fish or a thousand and prices can be well below those of the shops. The first stocking will be essentially of "bread and butter" fish while I can go to my favourite shop later for the more unusual ones. Incidentally I actually do have 10 tanks, all heavily planted or in the process of being planted, using a bottom layer of garden soil beneath the substrate. I've been very pleased with the results, plant growth has been excellent even under normal lighting levels. All tanks will have been planted and running for 4 - 10 weeks before fish go in, so definitely not "new".
The only fish I have so far are ones which came with some of the tanks (I've bought them all from EBay used, at a fraction of new price). These fish are a mixed bag, basically those which had managed to survive the tender mercies of their previous owners, but they all seem pretty happy and healthy in their new plant-filled homes, two of my tanks which have essentially undergone silent cycling.
I have "cycled" another 4 tanks to my satisfaction with ammonia, though it may be that the dense planting has "interfered" with the tests, but I don't really worry about that. Perhaps because I'm an ecologist, I prefer to see the whole tank as a system and I know that the complete system, no doubt a combination of filter bacteria and plants, is able to remove a lot of ammonia quickly. I seeded all the filters with "squished" water from an established filter and I've also been adding the ammonia at 7 pm, immediately after switching off the tank lights, which are left off until 9 am the next morning. There has thus been 14 hours of darkness after the ammonia dose, which was primarily to reduce the likelihood of algae (which have not appeared) but also perhaps to give the bacteria an edge over the plants. I've increased the maintenance dose by 50% as it was being used up in about 16 hours.
Incidentally, setting up 10 tanks from scratch isn't as daft as it may sound. None is large, the biggest are about 110 - 120 litres, as big as I can lift and move on my own. Having more, but smaller, tanks means that I can establish a number of small communities with less likelihood of personality clashes. I'm restricting myself to smaller fish, generally up to a maximum of 6 cms but often much smaller, mainly tetras, smaller cyprinids and corydoras. All are shoaling fish which will be in groups of 6 to 10.
I'll give progress reports as things get going, if it's of interest.