ATP's real appeal is speed. They can get you all the ratings required to be a regional FO, and do it fast. You'd have lots of multi-time by the time your out of there, not a lot of total time, and probably some time in an CRJ simulator. You'd be used to flows, memory items, and running checklists, what you would probably lake though, is serious real world flying experience. And what you'd gain is lots of bills to pay.

For 20k at a small FBO, you could probably accomplish what would take 60k at a large ATP styled school. Youve already mentioned that you're a computer nut, so, i'd stay away from anything that has one. You'll be perfectly at home in the RJ with it's glass cockpit and FMS computer. It's not bad to have some practical experience with a aviation GPS at some point, but, the cheaper airplanes will be the smaller and less complex ones. Get your ratings in 150s and 172's, find a duchess, or better yet, one of those flying potatos (someone will know what i'm talking about) to get some multi time in. Instruct, (which while you won't make lots of $$) you'll be home every night, and fly every day, it's not a bad deal. Then head off to the airline world, you'll have much more practical knowledge, probably more flight time, and better experiences. Also, if you nearly kill yourself some in an Apache (the flying potato) then you'll have better stories for that airline interview.