Your situation is not unique, a lot of expats have Chinese girlfriends, so that’s good: there are plenty of websites built to serve customers with exactly your needs, and contacting them is easy.
Are you suggesting there is no florist in Chengdu where someone can speak English, will not accept a Skype-call, and an overseas credit card won’t be accepted or can be used in Chengdu?
Looking for a florist in Chengdu who speaks English, will accept your Skype call, accept payment via Western credit card, and deliver in Chengdu is probably only going to waste a lot of your time. Let alone one that will charge you “near nothing” or come with some kind of personal recommendation (recommending a florist here is kind of like recommending a gas station – you just go to the one nearest you). I’m just telling the truth and trying to save you some time.