This guide may help. https://dell.to/3Ndbmj2 Most likely yes, you will want a switch between servers and clients unless it is a small network. 

What DELL switch do you recommend?

Then you probably don't need a switch and can just direct connect. 

For HyperV vswitch setup, will you need any additional 10Gb switch?

I have budget for both hyperv switch and SAN switch.

Hi,

Thanks for your question. It depends on how much expansion in the future you will have. It will make things easier if you have a lot of devices connecting. It may be helpful to go through the install guide for Unity. https://dell.to/3MNEV9v

Let us know if there is anything else we can help you with.

Hi Josh

At most it will expand by 1 more server. Unity capacity will not increase

One of the S series switches is best. https://dell.to/3WRTkpM High end N series would work as well. https://dell.to/3NbfqiL

You havent told us of your Hosts have BaseT or SFP+ ports.

S4112T = Half sized 12x10G BaseT and 3x100G for VLTi and optional 4x25G when using a Breakout cable
S4112F = same as above but 12xSFP+
S5212F = Half sized 12xSFP28 and 3x100G..

Thats what we used when dealing with small cluster sizes. For the s4112F/s5212 you can buy SFP(+)->BaseT transceiver when having a need to connecting a few BaseT devices like iDRAC or UPS. If you have more than a few.... go with the s4112T.

If you get ONE 19" mounting kit you can place 2 switches into it so you get redundancy with 2x12 ports and only need space for a single 19" 1U.

Each switch comes with 2x PSU.

Regards,
Joerg

The DS6505 is a fiber channel switch not an ethernet switch. https://dell.to/3OX3inG

Hi

The provider is offering me the DS-6505-24 but I want the DELL brand.

The servers have the X710 2x10GB SFP+ i350 2x1GB NDC 6VDPG card from DELL. It is valid? Or do I request more connections?

The DS6505  is a FC Switch. You told us that you would like to use Direct Connect FC from Hosts to the Unity. So there is no need for a FibreChannel fabric. The DS6505 is a brocade one and is available from DellEMC as well. But again.. you dont need it.

For your Ethernet go for the S4112F or S5212F because your Hosts have 2xSFP+ which gives 2x10GbE for just the network.

If you stay on Dell brand you can go with the "cheap" DirectAttachedCables aka DAC which are available in 1,3 or 5 meters length. So you dont need Optional Transceivers for NIC and on Switch side. Just 2xDAC per Host.

Regards,
Joerg