Hello,
Welcome to the website.
DotNetNuke is a good solution and will be able to handle it easily.
The performance of the DNN install is due to the performance of the server with your hosting provider.
I would have a read of the comments of the various hosting providers in this section of the forum as it should give you a good idea of how other users rate various hosting providers. If you want to compare performance, DNN Creative uses
Power DNNthe performance is very good with good support, you can read comments from other powerdnn customers in this forum
Yes you can upload your localhost DNN install to your hosting provider, have a look here:
Hopefully that should get you started along the right path, good luck with your project and if you have any further questions, please feel free to ask as many questions as you need in the DNN Creative forum.
Cheers,
Lee