Most of the SF free syrups are Splenda/sucralose. If you want to avoid that can also try flavored stevia drops...I’m currently using Vanilla and English Toffee from SweetLeaf brand. do not use too much stevia, only a few drops, it gets bitter if overdo amount.

I second the cold brew idea...can buy it at Trader Joe's in US, but I have made it myself too. The TJs says good 30 days from opening.