Crowdcube is a platform for you to raise funds and thus does not make a recommendation or provide legal advice on what shares should be offered.
That said, the majority of businesses we work with choose to adopt our standard share class model of A Ordinary shares (with voting and pre-emption rights) and B Investment shares (which do not have these rights but do have equal rights to capital distributions and dividends), with an investment threshold to discriminate between the two (ie. Those investing more than £x receive A shares). This approach is intended to strike a balance between reasonable investor protections and straightforward corporate governance.
You should consider how investors are likely to view the rights you are offering - severely restricting the rights and protections available to investors may reduce your chances of a successful round.