We are actively looking for a new web host. We are a web design company and are not server administrators. We are having HUGE problems with our current server being down too much and we HAVE to change immediately.

We are running about 5 e-commerce sites (zen-cart) with SSLs and we're running about 4 other SSLs on non-ecomm sites. We have many other static sites with about 75 total domains. We need Linux/Apache servers running PHP and MySQL. We are growing and will continue growing so we will be adding more websites, databases, etc.

Minimum Requirements:
VERY good uptime
don't have to talk to a machine
will fix problems even in the middle of the night
established company with references
spam filter of some sort
control panel (DirectAdmin preferably)
Unlimited IP addresses (we only use them if we have to)
live website statistics
web mail
SSH capabilities

Currently, we have four servers set up basically as follows:
Processor Name Intel(R) Pentium(R) 4 CPU 2.80GHz
Vendor ID GenuineIntel
Processor Speed (MHz) 2795.527
Total Memory 969584 kB
Free Memory 27168 kB
Total Swap Memory 1015800 kB
Free Swap Memory 1015640 kB
System Uptime 2 Days, 23 Hours and 4 Minutes
Apache 1.3.37 Running
DirectAdmin 1.28.1 Running
Exim 4.50 Running
MySQL 4.1.11 Running
Named 9.2.4 Running
ProFTPd 1.2.10 Running
sshd Running
dovecot 1.0.rc10 Running

We aren't server admins, so we really don't know if we need dedicated servers, co-located, or what. We need help configuring server(s) to fit our needs while understanding our growth potential.

Any advice or information would be helpful and appreciated.