Due to the difficulty now and a number of high h/s miners, solo mining probably isn't a viable option. All being said, consideration has to be taken into account that you won't be running multi GPU setups and cost/wattage is negligable.

Also with ARO's block reward system, mining in the pool can earn you 390 ARO if you actually "win" the block. (Originally starting at 400 ARO block reward, this decreases after every 10800 blocks solved, it is currently at 390.)

While not impossible to solo mine (after all, a 1 .5 h/s miner hit a block pool mining) it is probably more beneficial in the long run to pool mine.

I would advise though if you are considering solo mining, there is a guide for setting up your own node over on the ARO forum - https://forum.arionum.com/

Good luck