Hi there! My name is Oleksandr, I am from Ukraine.
I read your job offer carefully and would like to work with you as I have necessary skills. Here are answers to your questions:
1) I will use Quickbook SDK for .NET for this project
2) I had a project last summer with this technology, I moved data from MS SQL to Quickboks. So, if interested, I can tell you more about this. You can check this link - https://www.freelancer.com/projects/C-Sharp-Programming/App-using-Quickbooks-WebConnect-API/ It's that project
However, I would like to have more information about your project in order to be able to give you proper price and time frames. So, can we discuss your tasks in private messages?
Some words about me:
I am a skilled C# developer with more than 5 years of experience. I am qualified in such technologies as C#, NET, ASP.NET, WPF, different APIs, JavaScript, AngularJS, jQuery, HTML5, CSS3, MS SQL Server, MySQL and other technologies. With full list of my skills you can get acquainted on my profile page.
Looking forward to your reply.
Best regards,
Oleksandr