No experience with the equipment you've described (although I have owned the original Project Phono Box-it was nothing to get excited about); I would think that it might almost be a wash (in light of the fact that the Phono Box II is supposed to be quite a bit better than the original).
Keep in mind that in many cases the real limiting factor with these entry level "package" tables is a throwaway cartridge. My gut feeling is that, if you can't upgrade for a couple of years, the way to go would be to economize on the Debut with the Tube Box, particularly if you could have the included cartridge totally credited towards something like the AT 440 MLa.
Either way, you should probably look at upgrading the cartridge and/or stylus (without totally blowing your brains out of course) before you bring the table home to get the most out of what you are spending.
Keep in mind that in many cases the real limiting factor with these entry level "package" tables is a throwaway cartridge. My gut feeling is that, if you can't upgrade for a couple of years, the way to go would be to economize on the Debut with the Tube Box, particularly if you could have the included cartridge totally credited towards something like the AT 440 MLa.
Either way, you should probably look at upgrading the cartridge and/or stylus (without totally blowing your brains out of course) before you bring the table home to get the most out of what you are spending.