Resa, I've added a word to my last post so it makes a bit more sense now
Fish shops are very variable in their advice about bottled bacteria (the filter activator) probably caused by a lack of understanding. The theory is that these bottles contain both ammonia eaters and nitrite eaters. When you add them to the tank, they would like you to think they instantly get to work and will make the tank safe for fish. The problems are several.
First, it is quite possible that all the bacteria in the bottle have died since they were put in there. Bacteria are living organisms which need food and air to survive - neither of these will last long in a sealed bottle.
Second, it is quite possible that the wrong species of nitrite eaters was put in the bottle, though is less common than it used to be, the manufacturers have realised they had the wrong one and changed.
And any living bacteria will be killed if the bottle gets too hot or too cold anywhere on its journey from the factory to your tank.
Then there's the fact that the bacteria live in the biofilm that coats everything in the tank, not free in the water. It takes a while for the bacteria to establish themselves.
Some contain spores which have to 'come to life' to start growing (if they work at all)
The instructions on the packs I have read say to add fish slowly as with a fish-in cycle. Many shops say to add all the fish at once despite what the packs say.
With the reading I have done, there is not one bottled bacteria that has worked every time for everyone who has used it. Some never work, others work some of the time - in the latter case the failures are usually put down to incorrect storage.
The ones that work most often are Dr Tim's One and Only (mainly sold in the USA) and Tetra Safe Start. But they don't work every time. Of course, there may be manufacturers in France that don't sell their products in the UK so I've never heard of them.
The safest thing is to add ammonia to test whether or not the activator has worked. That way, you won't find yourself unexpectedly doing a fish-in cycle with all the water changes that involves. If the ammonia is processed to nitrite and then onto nitrate immediately, good you've found one that does work. If the ammonia doesn't disappear overnight, you'll know it doesn't contain any ammonia eaters - or not very many. If the ammonia does drop quickly but you then get a build up of nitrite, you'll know the activator doesn't contain any nitrite eaters. In either of these cases, you can then proceed slowly with a fish-in cycle if you choose that method, or continue adding ammonia and do a fishless cycle.
There are two 'how to' threads in the 'Filtration and Cycling' section near the bottom of the page with step by step guides to the two methods.
If you choose to do a fishless cycle using ammonia solution dosed to 5ppm, you'll be able to get three quarters of your proposed list at once when the cycle finishes.