@Anthony Emtman hit the nail on the head. At your size, if you are looking to maintain your company as-is and are comfortable with your portfolio, I would recommend leaning more towards a bookkeeper. It will likely be worth it to pay for someone who is familiar/specializes in real estate.
However, if you are looking to scale your company, a strategic advisor will be crucial. Someone who manages your books, advises on investment and tax strategy, and can help you systematize your business will be what you need.
Hiring a controller a CFO will likely pay for itself, but at your size- a full time controller or CFO would probably be out of budget.
Do a search here on BP for CPAs that can act as an outsourced CFO or controller. They'll take care of your books, all compliance, tax prep/strategy, and help you build out and automate your accounting systems.
Please make sure if you go the outsourced CFO/controller route- do not hire someone who bills by the hour.
You want them to value effectiveness and efficiency over time... plus, you're buying results, not time.
Once again- right now, you're probably good with a RE Bookkeeper, but if you continue to grow, start looking for an outsourced CFO/Controller.