Do not let a salesperson pressure you into purchasing solar panels. A solar energy system is an important investment and you should take the time to compare your different options. If a vendor feels the need to pressure you, they might not be confident about the quality of their products.
Keep shade issues in mind when installing solar panels. A panel that loses a quarter of its light can lose half its power production. The main thing to keep in mind is tree foliage. Are any trees going to grow in between the panels and sunlight? Consider trimming them back a little.
MY SOLAR TEST I DID WITH MY VAC TUBES ALSO SHOWED HOW I BUILT THEM.