There are a number of very good kits out there, but the "best" kits for one company won't necessarily be equally good for another. Factors include: price, ease of use / equipment required, allergens available, sensitivity, cross-reactivity, whether you need product and/or surface testing, and how complicated it will be to validate the kit for your specific matrices.
There are plenty of cases where any of the kits available will do just fine. And there are some cases where no kit on the market is going to be effective - for example, attempting to use a soy kit to detect soy lecithin.
There are also kits that do not test for specific allergens, but just for (relatively) low levels of protein on surfaces. These can play an important role in allergen management, too.
It would be helpful to know more about your workplace. Which allergens are in some but not all of your products? What form of allergen (powder, raw material, etc), what types of products? Are there allergens you don't work with - but your suppliers do? Prior to your arrival, has your facility done any sort of allergen monitoring?
Happy to chat more if helpful.