To obtain the Aklex you have two options, being the first one to buy them through the Market Console or directly from the Arsenal of your ship. It will cost you 190 Platinum, but if you choose this option you also get an extra weapon slot in your inventory and an Orokin Catalyst already installed.
The second option is to buy the Blueprint and craft it in the Foundry of your ship. To do that you need the required resources to star the crafting and wait until it is completed. This requires time and dedication.