Licensing for Access Databases for Sales via Website (e-junkie?)

What I need or require: I have several Microsoft Access databases I'd like to start selling on my website. I'd like to offer a free trial (either a limited number of uses or days) and then prompt the user to purchase a registration key through my website. What I already have versus what the provider will build: I have the database files and my website ready. I'd like either a VBA module or a dll (written in .NET) that will manage the licensing for these applications. I have access to a hosted SQL server and Visual Studio – if you can get me started in the right direction with the code, I can probably make the final modifications. Other context/requirements that providers will need to know: I'd like to make sure the registration key only works for the particular database purchased and only for the number of computers specified. I'd also like to make sure that the user can't just re-download the trial application again (unique/expiring URLs?). I'm curious about using a service like e-junkie ([login to view URL]) and am open to any other third-party solutions as long as they are easy to use and understand (for both me and my customer). When checking to see if the trial is within a valid date range, I would prefer to check the time through an internet server such as NIST's Internet Time Service (or similar) rather than the computer's date and time (which can easily be changed). My customers may not always be connected to the internet. I'd like to make sure that the initial registration key check is performed via the internet (a call to the SQL server?), but that it's not required to have an internet call afterwards. Specific expertise that I am seeking: First and foremost, I'd like the Provider to have a strong command of the English language. There may be a lot of back and forth as I get more information regarding what's possible and nail down the requirements for this project. I'm looking for a Provider who can do most of the work and explain to me what they've done so I can make any changes needed in the future. The Provider should have experience with web calls in VBA/VB/VB.NET and with general software licensing. If you have examples of this already available (specifically, Access database systems protected by code you've written) please provide links. I will need the original source code for this solution, so the Provider should be able to produce clean, well-commented code. Timeframe for delivery: Within the next 6-8 weeks. Budget: I really don't know what all this will entail, so I've posted this with a budget of $30-250. If you feel the need to bid outside this range, please do so.