RE Equipment:
I like to grow as a hobby, and I earn well so I dont have advice on how to do this "on the cheap". My best advice, based on what you have written is:
if you want a 4x8, any tent will do...i buy Gorilla Grow Tents, they are very high quality but expensive...most other tents are the similar.
lights are a very debatable topic. my bloom room has tall ceilings and so im converting myself to Gavita with LEDs for angled side lighting. My favorite LEDs of the 3 brands ive used is Viparspectra. They are pretty inexpensive on amazon. 89 for 300 watts, 189 for 600 and 399 for 1200. For your single tent ide go with 2x 1200w and maybe drop a CFL in each corner. Alternatively you could do 4x 600s or 8x 300s etc. Heat with these exists but its minimal.