For all LSx I use HPT. I have ordered a lot of credits and never had a problem.
A few times when I was in the middle of nowhere with no internet access, I just picked my Android cell phone and ordered credits. The new license key arrived at my email APP in less than 30 seconds. Then I just typed the new key to the software and I was tuning.
HPT uses CC and paypal, I always use paypal and never had any problem with foreign transactions.