I, and others, do not advise buying 'kits' on ebay, unless the kit is just a body and a lens you already want.
Even the good dealers, and I don't know the one you put up, put together a lot of junk in their kits. The tripods especially usually turn out to be something you could get from Walmart.
The only filters you are likely to need for a dslr are circular polarizer and neutral density.
Some like a uv for protection but if you are going to put glass in front of your expensive lens glass, it better be of good quality too or you might as well buy cheap lenses.
You will notice they don't give you brand names of the 'extras' for the most part. There is no way to research them to see if they are any good.
The dealer on ebay I use is Cameta which gets good reviews but they also put together these kits. You'll be paying a bunch of money for these 'extras' and you will be better off in the long run, researching filters, tripods, bags, etc and get what you really want and/or need.
Which camera, I cannot say. I do know the D90 is renowned for being able to shoot at high iso with some of the best noise performance in the market.
When you go Nikon or Canon or any other body, you are buying into a 'system' Nikon requires Nikon lenses or compatible and the same for Canon or any other brand. Things like who has better flash, who makes the lenses I want, plus a myriad of other peripherals need to be taken into account though both will have about anything you want I'd think.
Google reviews for the 70-300 lenses for each manufacturer. Each has positives and negatives. The price of the Canon does seem rather high to me also but I don't know if it is that much better a lens or if its better at all.

I wish you luck but strongly advise against buying a kit.