Make sure the dimensions of any replacement are identical to the existing OE battery and look for a 4 or 5-year warranty from a well-known maker.
I'd add that the physical size is very important to be mindful of as as engine bays are normally crowded and do watch out for bigger physical batteries encroaching on excess heat areas like CATS / Turbos etc.
I'm guessing your original is badged Solite? which is a Hyundai Group (as you might expect ) sub division also known as Hyundai Enercell from what Google reckons
I've always found that OEM batteries are normally "just enough" with regard to CCA and AmpHours
I've always tried to go higher (physical dimensions allowing).
As an example the Solite on my Venga was 410AH and in winter was noticeably slower at turning the car over.
When the Solite died (annoyingly when I'd just done a freezer shop at Costco, thank heavens for retired in laws), I replaced it with an Exide from Eurocarparts at 550AH with 3 year warranty. Spins the car much faster in Winter and no adverse affects or warning lights (and mine does have a charge sensor so isn't just passive positive and negative connections).
Do remember that your radio may need resetting (so note any channels you like to listen to), you may also get an EPS light which often just needs you to turn the steering fully left and then fully right and then back to centre to reset the steering motor range and switch off and back on again to clear the light.
There is some discussion over whether stop / start enabled cars need an AGM battery (which might be what the dealer is qutoing for) but many on here have used a "normal" lead acid wet cell battery and had no issues.