The flex can be done by needle as well, like I did Here 
Do you know what kind of cards that are used for your gym- & garage-card?
Try to download the app NFC tools and scan the cards. If you get any info, please post a screenshot so we can help you with choosing the right implant
Do you know what kind of cards the lock system you plan to use for your house uses? Or what is the name of the system you’re planing on using?