The WRT1900ACS would be a best fit between the two options imo. Both really need to be updated to current builds.
The Linksys upgrade to current 23.05.2 stable will move you to DSA, so you will not be able to carry configs over from 19.07 - take a backup for reference before upgrading. (For the record, most if not all package configs will survive intact, but system & network will need attention).
I’d also suggest using a current ‘main’ Snapshot build for the Linksys to take advantage of very recent updates to mwlwifi that benefit the 1900 but aren’t included with 23.05.2 stable.
You can use the current Snapshot build w/out LuCI or there is an alternative Community Build here that is well respected.