Hi there,
You don't have to do much differently for 'niche' sites in terms of SEO than any non-niche site, to be honest. You will still need to choose your keywords, put together some great content, manage your site structure and on-page optimisation well and ensure a great user experience.
After that your link building efforts are fairly simliar in that you'll need to look for good linking opportunities. Look at your competitors for the keywords you're targeting and then maybe look at some advanced search queries:-
http://www.seomoz.org/blog/9-actionable-tips-for-link-prospecting
Niche Communities The thing I would suggest is getting involved in communities based around your niche - maybe hook into some blogs or forums, or other community types and be of use to the people there - get to know people well (don't just see it as 'link building'). If you're in a niche then you want to get known in that niche.
Social Media Look up some communities through social media or do keyword searches in those site to identify people you could get involved with or get to know.
Backlinks How many links it takes to get you noticed? How long is a piece of string? It depends on the quality of the sites linking to you and what your competitors are up to - that will change niche-to-niche.
Web Designer You should be able to get any web designer to create your niche site but I would suggest you go with a designer who understands SEO in order to get the site structure and content right before the site goes live. Ensure you get an Italian Copywriter to look over the content so that keywords are inserted in a natural, linguistically acceptable way - i.e. it reads well.
Hope this is of use to you 