ABB (now FIMER) and Sungrow are both really good inverter options, and in our top 5. I would be happy with either inverter on my roof, but given the UNO brand has recently moved from ABB to a new company FIMER, perhaps Sungrow is a more stable option? See our reviews below:
They are very different quotes, obviously the last one being twice the size of the first two. What are you hoping to achieve with solar? You want to produce as much power as you consume? Or fastest payback? Or something else.