It's a lot harder than you think, if you want to equal the top end mould/ handmade papers. The mechanics are relatively easy, but forming sheets consistently, from a suitably non-contaminated pulp beaten to a suitable fibre length & sized with a non-reactive size, and ensuring that you press them correctly so that you get a suitable surface, may end up eating months of your time to learn the skills. Give it a go, but you may find that the Ruscombe Mill handmade papers (or similar) are a better option, and I recall the minimum order for special makings is not large. You can even get custom moulds made (not cheap at all, but it'll last forever if well looked after) & have your own watermark incorporated - see
http://papermouldmaker.com/