You would do well keeping your support system in a completely isolated place. But if you are starting off small, and are keeping everything under one roof, including sales, and support, isolate sales from support. Give support most priority. Keep them on an isolated intercom circuit. Give them the best power backup. Have more than one internet connection for them, even if you have a best internet service provider’s connection in your region.

Install seperate local servers for the sales, billing and the support teams. Always keep them on seperate LAN connections on seperate internet connections. You wouldnt want your sales people to know which client is having problems, and your support to know how much sales is being done. Though support people may guess that from the number of new accounts that are bing created, it is best to keep them all isolated.

Provide seperate PCs for each of your staff. If you have 3 support guys, one working on each shift, give them an induvidual PC, 1 for each, and dont let them share a common PC. They should be able to access the details and everything that they need from a common server to which all support PCs are connected. There is no point in having more than 2 shifts for sales, so they might as well share PCs.

Though you are confident about your network installation, wires can get disconnected at any time. So it is always best to connect your PCs thru wifi. Atleast you will be able to switch to another ISP line immediately if you have problems in one.

Make sure that you get only a Split AC, that comes with a seperate outdoor unit, so that people can save themselves from the noise that the AC produces.

Seat your staff very close to a loo, so that they dont spend too much time wandering to the loo once in a while. Also, have an office attendent or two, who would bring refreshments directly to them, so that they dont have to take the excuse of walking to the coffee machine ever half hour.

If you have got loadshedding in your area, or if your area is a victim of a very frequent power blackout, it is best to go for a sinewave UPS, as running computers on Generators is not advisable. You could however install generators for the ACs and lights.

This should do, to start up a small scale office for providing web hosting services