It depends on what you are looking to do. Are you managing an account solely for yourself or for others? Are you looking to investing in individual stocks, ETF Option or mutual/index funds?
I use Charles Schwab and am pretty happy, although I don’t like paying a $50-$60 ticket charge for some mutual fund trades.
IB is great, it seems a lot of people on this forum use them. But you do need $10K minimum to open an account (which is right at the OP’s limit). They don’t have “inactivity fees”, but they do have various fees depending on how much data you want (and some of those fees are waived if you trade a lot in a given month). Their “Trader Work Station” stand-alone app is super powerful, but does takes some time to understand and customize for your needs.