VPS would be the best option for this requirements. All our Servers have 100 Mbps Ethernet card and they are connected to 1 Gbps Switches. This switches are connected to 2 x 10 Gbps uplink so you should have no concerns related to network speed.
You should consider only VPS to host a video sharing website as all the custom configurations of apache and php can be done on a VPS while few things like ffmpeg wont be possible on a semi-dedicated server.
All our VPSes and
Dedicated Servers are fully managed so you wont have any problem in upgrading to a
Dedicated Server in future as we take care of migration work for those who upgrade from
VPS =>
Dedicated Server.