Help with future setup

Hi all.
I'm currently running a Dahua VTO INTIPRDSB, paired with a INTIPMONDW, and 2 x HDW4431C IP Cameras.
All is running well, however I'm not recording anything.
I'd also like to add another 4 IP Cameras.
Should I simply just add in a Dahua NVR, or should I look at going the Blue Iris route?
Would like to possibly record 24/7 and happy to save about 2 weeks worth before over writing.

You should record 24/7 in order to not miss anything.

The decision of BI vs. NVR is up to you. Each one has its pros and cons. I went the BI route back in 2018 and have not had any regrets. But I never had an NVR either. Some folks here have had both and have stated they prefer BI. Other well-respected folks here have an NVR and are just fine with it.

I have had user experience with an Hikvision NVR recently and found that it was not as flexible as my BI setup. Trying to view past events, export a video, and select specific cams for review together and export was not as straight forward as it is in BI. Now that could be the specific NVR or my limited knowledge of it. I like the fact that you can really customize the BI experience and that the developer is constantly upgrading and adding to the software.