sfq or prio qdisc?

Hello,

I am hesistant to chose sfq or prio qdisc for my router. First, I'll
introduce my class hierarchy in order to make you more familiar with my
issue.
It is regarding network router that makes NAT, broadly speaking. The
capacity of the link is ca 1024kbps, there are 124 LAN users so far.

On the top of my hierarchy is htb qdisc and htb class attached to it. This
parent class has 124 htb subclasses, each with rate 1024/124kbps, ceil
1024kbps (not precisely, I subtracted 10 percent of the capacity). Earlier I
had attached a sfq qdisc to each htb sublass to ensure fair conditions for
www, mail, etc. But it seems fair conditions are not the best choice. Why
provide heavy bulk traffic with the same priority like interactive ftp
command traffic? I've read that prio qdisc creates by default 3 classes that
are in fact 3 fifo queues. Each such a queue has its own priority, these are
from 0 to 2, 0 is the higher. Prio is able to direct packets to appropriate
queue without additional filters, considering they TOS field, that can I
alter using iptables. It seems, I can take control and decide how fast each
kind off traffic will be processed.

Please keep in mind, my main goal is to split my whole link between 124
users and provide each user with properly prioritized bandwidth.

Am I right regarding my solution?

thanks in advance,
Rafal