Too bad you have to get an iPhone
But a free phone is a free phone....I'd be inclined to switch as well (but really, I'd probably stick with Android).
Anyways, I am sortof in the same boat as you, except I'm the opposite: I have a company-bought iPad2 and an Android phone. Been doing it since the iPad2 was released. It's really not too bad, but I'll detail my experiences.
Your biggest problem is going to be apps...more importantly having to double-purchase things that aren't free. But really, other than the money issue (which may or may not be a lot to you), it's easy enough to get around, so here are my recommendations and how I live my life between the iPad/Android/PC world.
- I do not buy ANYTHING from the Apple ecosystem other than apps. No iBooks or anything from iTunes or anything like that. While you can use iTunes music on other devices, things like iBooks only work on iDevices, along with many of their other services, so I just stay the hell away from buying from the Apple stores.
- Music: I've uploaded my collection to Google Music and I can listen to that on all my devices. You can download the music (for local/non-connected playing) and use it on the iDevice. So any music purchases come from there too (admittedly, I stream most of my music with Pandora or Slacker, so I'm not buying a lot of music these days)
- Books: I buy them from Kindle. It syncs to all my devices and works flawlessly.
- Movies: Honestly, I just use Netflix....I have no recommendation on where to buy them from. Netflix works on everything though, if you use it. If not, maybe someone else has a recommendation
- Calendar: Google Calendar for personal stuff and syncs to everything...even the default calendar app on my iPad. I also use my work's Exchange (which also syncs to my calendar on everything).
- Photos: Picasa (which will probably be merging with Google+). Photos on my phone sync automatically to it once connected to Wireless, and my iPad syncs as well (although typically I'm only viewing photos on myiPad...not taking them).
- Browser: Chrome on everything. Syncs my bookmarks across all the devices, as well as my tabs.
- I stick with apps that will sync across all my devices. Just some of those include TripIt (for my travel stuff), Evernote for any notes I take, most of the Google products (Music, Picasa, Gmail, Calendar, etc), Dropbox, Google Drive, etc.
In fact, I even have an "Apple Crap" folder on the last screen of my iPad that I've moved the Apple-only apps into that I'll never use. Those include: iBooks, Reminders, Game Center, Safari, iTunes, Music, FaceTime (if someone wants to video chat, they can use Skype like everyone else, or I'm slowly convincing contacts to start using Google+), Videos, and Notes. Like I said, I have replacements for all of those (that work and sync to all my devices, not just to iDevices), and even though some (like Safari) will always open as the default program, I'll never actually open it up manually to use it, so it gets thrown into the "Apple crap" folder, never to be seen again.....well, unless I need to help someone like you out and I need to rattle off all the stuff that in it
In short, it's not horrible living in a multi-ecosystem environment....but again, my Android phone is my primary daily driver that gets 90% of the use, leaving my IPad kindof relegated to when I'm home relaxing on the couch and want to read a book on it or the tech blogs and stuff and just want a bigger screen than my Galaxy Siii. You'll be the opposite with the iPhone as your daily driver that you'll be using all the time, so your needs might be different.
Hope that helps.