Additional musings to the above information. Some is restating, some is new info
SBS Essentials does not have Sharepoint and Exchange as does SBS Standard. You can buy the Premium upgrade which will give you second server and SQL server standard but it costs more than Essentials.
It does have 25 CALs built in, simplifying the cost and keeping up with them. (I think SBS Standard comes with 5.)
Gigabit internet made more of a speed difference in my system than anything had in a long time. It requires each computer to have a Ethernet connector that a gigabit and a gigabit switch (as above.) Wiring has to meet specs too, but you probably have 5e wiring which will be sufficient.
If you are going to keep the laptops and they are more than 2-3 years old, you might have to get gigabit adapters. Most of the newer ones have gigabit built in. If you are replacing them, there is a thread about desktop vs laptop that is worth reading.
A good IT person will help you choose the options you need and balance the cost.
