Strips are just plain inaccurate (read: garbage). They will also cost 10x the amount of money over the long haul vs a kit. The liquid tests are as accurate of tests as you can use for home aquarium testing. But, you must read & follow the directions for performing the tests- the only inaccuracies are typically user errors.
The aqua safe is suitable as a dechlorinator but it does not detox ammonia and nitrite as Prime or Amquel Plus do.
If you let your tank sit with fish for 5-6 wks, all your going to wind up with is either permanently damaged or dead fish. Ammonia and nitrite are poison to fish. If you are not willing to do the work a fish-in cycle requires to make sure your fish survive a cycle unharmed, I would seriously consider returning them and doing a fish less cycle instead. You asked for advice & I am offering it- feel free to make your decisions.