Is a Mackie 24x8 mixer the only choice? No. The Mackie has not-so-great-sounding EQ, the mic preamps are just OK. It's strengths are reliability, lots of options and features (like a built-in talkback mic), fairly clean, neutral sound, and the fact that it is still manufactured new and can be serviced. It will work for you and be dependable. You don't have to have an 8-buss console... a Mackie 1604 will work for a 2 ADAT setup if that's all you could afford. The 8-buss consoles offer more convenience and options.
There's lots of used choices of 8-buss models, like the Soundtracs Topaz & Project 8, Soundcraft Spirit & Ghost models, Allen & Heath. All are good choices. Probably the only manufacturer to stay away from are the Behringers, including analog and digital models, and perhaps the Mackie D8B, which is quickly becoming obsolete from a digital console design standpoint.