My dad's roped me in to a project of his that will require the renting of a server.

I know of a few companies, but I've no real knowledge of the market, and who's known for what.

We'll want about 100-150GB of space initially, which will probably rise. Bandwidth usage will likely be quite high as it'll have an ftp server attached to it.
At the very least i'd want shell access. I'd like to be able to install apps, too. Will need to be able to do CGI, too.

Uptime and backups are of equal, ultimate, importance.

What should I be looking at/for? Is there anything else we need to consider? Which companies are 'best'?

I've had good luck with 1and1.com -- they're certainly one of the largest players out there. The main trouble is the largest disk drive they offer on a root server is 120 GB. There are several from ev1servers.net that might meet your needs. I've never used easyspeedy, but they seem good and relatively inexpensive for what you get. There are a number of providers here and I've just named a few. You should do a bit of shopping around as deals change quickly in my experience.

I have been using http://www.pair.com for the last 7 or 8 years and have been very happy with them.

Before you decide whose server to go with run "Ping" on several server providers and compare the results.

More important than what server equipment the provider offers is what connectivity and support staff they have. If a provider does not have adequate connectivity, including several alternate connections to the backbone, they may take longer to serve your web pages or be down at critical times. They also need a reliable generator with adequate fuel supply to carry them through an extended power outage. With the recent blizzards in the US it is easy to see that a server provider could be without electricity for days if not weeks.

A lot of the 'server providers' are really resellers of someone else's services.

The problem with any reseller's service is you have no direct contact with the people who can reset a server if it goes down. You are dependent on the reseller who is often an individual who has a full time job somewhere and you have to wait until he gets home from work a few hours later to get a response to a support message. Since I run a business on the Internet I can't afford to wait or to deal with a reseller.

Investigate thoroughly. A lot of the resellers have pages that show a big facility but they are in fact just showing you the pictures of the server providers they are buying space from. Unless you dig into it you may be fooled into thinking you are dealing directly with the server provider.

Bill Tolle

I wouldn't base a decision on ping results, there are many other factors involved than comparing the results from your own connection to a server.