I'm not an electrician, but an electrical engineer, and I bought a complete DIY package with everything. Electrical code here in Denmark then only needs a certified electrician to do the connection to the the grid, which includes submitting the system to the grid operator, also so we can be paid for the surplus production.
If you know how to read the instructions, and plan your work, it's quite fun, and I'm pretty sure my panels are better secured (likely overkill) and more straight than 80% of the professional installs here, just because we took the time to do it thoroughly.
If you feel have the ability and you have the time, I would highly recommend it. But as another pointed out, try to find a kit with the mounting hardware!
I think I need more details: are you planning on running your house completely off-grid from solar, or Install (a set of) outlets that are powered by solar?