Yes it's totally ok to change the product & business model before meeting a VC and even after meeting him. Your job is to find product/market fit and almost every company goes through many iterations and even major changes to achieve that.

The only thing you shouldn't do (if you're raising money) is ask the VC to make the decision between both options for you. If your goal is to close funding from this VC within the next 90 days, you will need to project confidence that whatever choice you've made and that you're raising on, is the right one. If on the other hand, you really do want their opinion and aren't planning on raising soon, presenting both options and getting feedback can be very valuable IF, this VC has relevant experience in your space. One of the worst things a VC can do is offer up an opinion with conviction without having the experience or really even passion for the space the entrepreneur is in.

I'd be happy to talk to you by phone as early stage fundraising is an area I help a lot of Clarity members with. I've also answered a lot of other Clarity questions on early stage fundraising which can be seen from my profile here: http://www.clarity.fm/tomwilliams