Multi-Tiered Application Architecture Question

Hello all, I'm studying for the LTM 301a exam and one of the topics is multi-tiered architecture. So I thought I'd come here to the experts who have way more experience than I do, for some advice to help me better understand it. Also, I find it odd that I'm not finding a whole lot on multi-tiered architecture in the F5 documentation. Or maybe I'm just not finding it?

Scenario:  Internet based clients connect to a web application hosted behind a Big-IP. I've got a single Big-IP running a Standard VS (VS-HTTP1) load balancing to a pool of web servers (10.10.1.0/24). The web servers will need to connect to a VS running on the Big-IP (VS-DB1) to be load balanced to a pool of MSSQL servers (10.10.2.0/24).            NOTE: See attached topology

Questions:

1. Should I use a standard VS for VS-DB1 as I see here in F5 documentation about using the Big-IP as a proxy for MSSQL? Or can I use an Internal VS for VS-DB1 because I'm really only needing the Big-IP to be a load balancer from the web app to the SQL servers and not a full proxy. I'm not sure which would be a better option.

- My thoughts on this are that using an Internal VS may save some resources on the Big-IP since it's not proxy'ing fro the SQL connections.

2. For the connection from the Web servers to the SQL servers I was thinking it would be best to use SA_Persistence, and if I do, then I shouldn't use any address translation because I don't want the source address to be manipulated.

Am I on the right path? Any other suggestions as far as settings or profiles I should consider for this scenario?

Thanks in advance !!!