I typed up this whole response and then got confused when I re-read your post. You said you don't want to work in public accounting, but you want to do corporate tax returns. Do you mean you don't want to work in a big-firm and want to run your own small public accounting practice, or that you want to work in industry and perform tax returns for the corporation you work for? I assumed you meant you were opening your own firm, so if that's not what you meant, this response will be useless, but here goes =P
In theory, if you get your license and a decent software program, you could open a firm and jump in with both feet. There are a lot of nuances in tax preparation, though, that I think are invaluable and that you can only get with some experience in a small firm.
I work in a firm with a total staff of 7, including the CPA and two office managers/receptionists. It's a very open-door policy and the CPA is a great manager and teacher, so I don't feel at all like I just do data entry, I feel like I'm being prepared to run my own firm. I think a tiny firm like this would be the best place to get experience because that's what it sounds like you want to open. I completely agree that going for a Big 4 job would be pointless if you want a real hands-on client management experience. I think the best option would be to find a small firm in the area and spend a tax season or two seeing how they manage things.
ANOTHER thing that might work (just brainstorming here). What if you opened up your own firm and initially just specialized in bookkeeping/payroll/etc? I know there are a few small firms around me that hire tax preparers seasonally. You could continue to run your bookkeeping practice and get tax experience under an established firm at the same time. The only thing that might be an issue (and potentially a big issue) is finding a firm that will work around a no-compete agreement.
Sorry I couldn't be more helpful, but that's my .02!
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