If one needs to make an Android application, what type of programmers would they need to recruit? A database for data storage will also be needed. Are there any generic apps which can be purchased off the Internet and modified to our custom needs, instead of developing an entirely new app?

For the app itself, you need Android developers. If you can't find any, you could make do with developers who can learn Android and have some taste for UI programming. For the database, I believe you're looking for one on the server-side. The easiest way is to choose a provider. Otherwise, you'd need to build one - see this case for example: There is source code for sale but I don't know about their quality. The Google Play developer account is US$25/year. You can use this to sell to any supported country. https://support.google.com/googleplay/android-developer/answer/113468?hl=en

You probably need some great programmers. The people in the startup I work for are all great programmers. None of them were experts and most weren't familiar with the technologies we are using before hand. But this wasn't an issue since we are experts in the new technologies now. So focus on finding good programmers (those are rare), doesn't matter if they did any android programming or not before hand.

To answer your first question, you need Android developers!!! (well, you can go with Java developers but these days Android development itself is a specialization). You can use any database of your choice .. leave it to the developer to recommend. If you are looking to re-purpose existing apps you will need to provide much more added value, so be sure you are doing that.