It is unlikely you will need First Party Cookie as VIsitor ID services AMCV_ cookie is set on the domain as First cookie by default and if you check the doc you should have same mid served on all of your domains as long you are using same Adobe ORg ID and demdex cookie is accepted. They is other ways to obtain same cookie if demdex cookie is not accepted but it is another matter all together.
so for tracking Server:
For best performance it is advised to use an RDC tracking server. This should decrease the response time from Adobe Servers. If you are using a tracking server that uses 2o7.net then it is advise to use the corresponding RDC server.
All report suites created in 2014 onwards are globally unique, meaning Adobe's servers can route traffic to the correct location without a data center designation. All report suites created or migrated to Singapore or Pacific Northwest are guaranteed to be globally unique, making sc.omtrdc.net always valide.
So use sc.omtrdc.net
Data collection requires a unique subdomain to keep visitor data separate across Adobe Marketing Cloud customers. It is prefixed to the data center address, and is generally your Adobe Analytics login company name with all spaces removed. You can technically use whatever subdomain you'd like, however it is highly recommended to be specific enough that:
No other Adobe Marketing Cloud customer would use it.
You are consistent with the subdomain across all report suites, especially if your organization uses a global report suite.
So the final trackin server should look like as follow: [NAMESPACE].sc.omtrdc.net
For account: this is the report suite ID that you used when you used when you created your report suite ID. Can be found under ADMIN >> Report suites in Adobe Analytics
account="[Report suite ID that you can find under Admin >> Report suites]"
I want one more thing to get clarified and seeking your advise for the same.
Actually we have a existing report suite in one of the account and we do created a new report suite in some other account ,So now i want to migrate my historical data(data transition) from existing report suite to new one. please enlighten on this what could be the best approach for smooth data transition as this activity needs to performed in production as well.
FYI - both the report suite exist in different account and belongs to adobe analytics.