If the other seminaries are anything like St. Vladimir's no, you can't work and do classes. There's no way to get it all done (unless someone paid you to study as a job, I suppose).
I don't know a lot about Holy Cross, my bishop doesn't send people there and my priest doesn't recommend it. We're not in the Greek jurisdiction though. Some of my friends who are here at St. Vlad's and are in the Greek jurisdiction were basically told to go elsewhere, however, because they weren't Greek. If you're not ethnically Greek you might look at going to Seminary through a different jurisdiction.
From what I've gathered, Holy Cross is very expensive and requires more time than other seminaries (I believe if you're pursuing ordination they require you to spend an academic year in Greece). There are ways of paying for it, but the first step in thinking about going to seminary is always to talk to your priest. Of course seminary is grad school, so you need an undergraduate degree first. Holy Cross Sem is attached to an undergraduate university, but the other seminaries aren't. The most useful degrees I've seen here have been in music, foreign languages, and philosophy, in that order.
If you end up thinking about St. Vlad's I can tell you what that process is like!
