Wanting Information On Building & Repairs

Hi, I am wanting to just do my own little gig at home buying broken phones and repairing to resell or even keep but I want to get them cosmetically appealing as well.

I would just like to know some reliable sources that sell genuine or high quality copies to use as replacements. For example, a iPhone 5s Grey. It needs the back and sides replaced aswell as a new home button.

Should I trust ebay? as the prices on here are still quite dear for if I want to resell as a small person. Also I am located in Australia if that helps at all. (the australian site as much much less items for sale.)