.Net 4 Winforms Price monitor & alert app

Need a multi-threaded WinForms application with the following facilities for sending something similar to Price alerts via SMS to subscribed users. - Configure multiple mysql database connections & xml paths. A particular table with 3-4 columns will be used. Another table containing user's phone number may need to be used for getting the phone numbers of users. - Read a 2-3 columns from the above to find the subscribed users, the subscribed prices and their phone numbers. - The price subscriptions have to be read every second to find out if there is any new subscription. The subscription will be different per [login to view URL] will generally be 2 prices per user. - Keep reading the price xml every second and see if any particular user's price has been reached. If yes send an SMS through a HTTP API that we'll provide. - Then update another table to inform that the alert has been given. - Continue the monitoring. - Need some feature to switch off, pause, switch on the alert for the particular connections. - Need a tray icon to hide the app The volume will be generally about 50 users subscribing and one update per second, which should not be very high. Please also suggest any ideas to handle heavy loads. The app should be written in .Net framework 4. Need to make sure it does not add too much load to mysql. Any suggestions welcome..