Short answer: it doesn't matter!
If you want to buy solar now, and buy batteries later when they are more affordable, that is a smart move.
So what kind of inverter should you buy?
The good news is that batteries can be added to any grid connect inverter using a method called AC Coupling. Without getting technical this simply means that you don't have to worry about buying a 'battery ready' inverter.
Some salespeople may try to convince you to get a 'hybrid inverter'. These are inverters especially designed to have batteries attached with a method called DC Coupling. Don't do it. Hybrid inverters are only compatible with a limited number of batteries (which may not still be on sale when you want to buy batteries in a few years) and they are more expensive than regular inverters.
With AC coupling and a regular inverter, you can add any AC coupled battery you like down the track and you are not adding any extra cost to the solar system you are buying today. Win win.