I recommend the Sony a6500. It is a 35mm mirrorless camera. It is half the size and weight and cost of a 35 mm Nikon. It has both a viewfinder and swing out viewing screen. Takes excellent photos and you can purchase interchangeable lenses. I use it for street photography and can shoot from the waist with a silent shutter feature. Recently taking night shots of the milkyway with an added wide angle lens and the pics are awesome. This camera is a really nice compromise between a point and shoot and big expensive 35mm camera. You should research more on mirrorless cameras.

Have you looked at the map for totality? http://www.eclipse2017.org/2017/maps.html
There just isn't anything to photograph unless you go to totality!!!! If you are within 300 miles of totality then just drive there very early on the 21st.
I tried to book a hotel in Boise Idaho 2 months ago and there was nothing left under $500 for the night before.

You wont see anything interesting unless you drive to an area that is in totality!!!!!! If you can't find a solar filter for your tamron lens, I suggest buying solar filter 4x4 sheets from B&H . You can make a cardboard frame and cut and tape the filter sheet into the frame. You want the frame easy to remove and replace so you can get C2, max totality (when you don't need the filter) and C3 shots of the eclipse. If you don't know what those are...start googling and you-tubing how to photograph the eclipse. Alan Dyer has a good short book.