Yes, both are okay. The one with "were" is mildly odd, but I'd call that a style problem. The context kind of encourages use of "were". In "If you {were/*are} rich you could afford this" and "If you {are/*were} rich you can afford this", the distribution is more strict, and corresponds to counterfactuality in the case of "were". As an isolated answer to a question like "Is this affordable?", selection of were vs. are in the response ("Sure, if you {are/were} rich") similarly correlates with the implication that we don't know if you are rich (are) vs. we know that you are not rich (were). By selecting "were" in your pair, you are suggesting that the addressee is not free, which is a way of defeating the inference that you've just imposed an obligation on the addressee (since the sentence is plainly a request for a meeting). Perhaps my judgement of oddness stems from my dislike of contorted ways of making requests.