You need a new website developer. Wp. org offers an open source content management system that you download and have full control over it. Wix is a SaaS deal. It's a closed box and you have little control over it. With wp, you get to build a website that is owned by you and you can upgrade, modify, tweak and host it anywhere you want. With wix, you get a lookalike. You can't move it, can't customize it, little flexibility, and forget about proper speed optimization. For a serious project, wix would be a part of a joke, not a part of the proposal.