Setting up multiple farms with different tools

We are possibly looking at setting up multiple farms 

1)  SharePoint/Project Server 2010 

2) SharePoint BI (great article on setting on BI farm here :http://www.jenunderwood.com/2013/10/30/setting-up-a-sharepoint-2013-bi-farm/)

I've heard from multiple BI professionals it's best to set up a separate farm for BI - due to the technicality (and other reasons)

My question is - whats the best way to implement a multi-farm infrastructure while not losing your mind/hair?

Or is it fairly simple to set up, implement, administer?  Do you have to cross certify them, 1 CA, or 2 SQL DBs?

I'd really appreciate any expertise, or comments on this.  And even experiences in implementing a multi-farm (or similar setup) 

Thanks

kbwrecker