I can't recommend you a suitable tablet, and I don't know if availability in the US is as wide as it is in the UK - but I can be fairly sure you can buy another N900 outright for less than you'll spend on a tablet, it's an option worth considering.

I just bought one almost new for £135 (GBP), which is barely over 1/4 of the launch price of £499, the plan being to use the new one whilst I repair the old one, and swap over as needed. You know you can sell whatever they give you in exchange and you know why you want an N900 - I know what I'd do.