The caps are sooooo cheap though. Like 50 cents/cap:

https://www.amazon.com/Growler-Plastic-Bottles-Kombucha-Brewing/dp/B0863YJCSP/ref=pd_lpo_328_t_2/143-0426692-4750617?_encoding=UTF8&pd_rd_i=B0863YJCSP&pd_rd_r=86e9ffcb-7ec6-4906-b519-8310846c22e2&pd_rd_w=SKtuJ&pd_rd_wg=e4Laa&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=V3T9KPSNYC4D0YP36HJ9&psc=1&refRID=V3T9KPSNYC4D0YP36HJ9

These will fit GT's bottles, I'm unsure what kind of booch you were getting. Metal caps aren't as reliable because they get a little bent out of shape, where the plastic caps are thick enough to form a good seal, and these ones have an 'upgraded' cone shaped liner that's supposed to be better somehow to the traditional F217 Polypropylene liner usually used.

Definitely your choice but I don't want you feeling like you wasted your money because you hadn't checked out all the options ya know? You'll get a little better experience with the flip top bottles for sure, you have a little better control for half-burping bottles to see if they carbonated, but you do pay out the butt for the bottles.