question regarding bandwidth through bastion host

[keithstevens @ acsinc . net (Keith Stevens)]

Is there a table or formula (s)  for calculating bandwidth or bps
throughput (or restriction thereof) for various hardware & software &
configuration combinations of a (hypothetical) bastion proxy server? Not to
start a war but what's faster than a speeding bullet and costs less than a
yaht? Which one has the best balance between performance, security and $?
What's the best at any cost? What's the worst piece of crap clog you've
ever seen?
Thanks for any useful information,
Keith