You can adjust the image in premiere, you don't need to export differently. There are indeed external monitors with frameline generators (I have one on my steadicam) but they cost more than your camera.
I have a 7D and I have the same issue currently. In my research I have found the world of sound is just as complex as the world of light. You would need to think about what you are shooting since as with lenses and bodies there is n such thing as "one to solution to them all " So here is what I came up with
The Rode Video Pro is about $229 US - it is a shotgun style mic good for directional sound. Where you point it to is where you will get most sound
The Rode video Stereo mic is about $299 US and is better for ambiance sound.
Both of these connect to your camera and is pretty portable. And for a seriously over priced $40 you can also get a fluffy catskin thingy to remove more wind noise
If you shoot Studio the Zoom H2n is about $231 US and is excellent if you want a portable audio recorder. In Post you just need to align the video and Audio tracks. As a Stills shooter I still need to figure this out
Now I have no issue with other manufacturers, but these are on my shortlist. B&H, Davomrmac and a few others have nice reviews on YouTube.
Documentary / highlight roll, not a static 'coaches/spectator' view. We are putting together highlight footage and our regular videographer will be unavailable. I am hoping to learn more from him, but I don't meet with him regularly, and I appreciate the info I get from this forum too.
We capture isolated plays, emotions of the moment.
Currently, I use a Induro GHb2 gimbal head (or a 327RC joystick, or a 57 series ballhead) on a Manfrotto 055CXPRo 4 (or a 695 series monopod) to stabilze a 70-200 2.8 II on either a 1dIV, 5d3 or 7d.
Also use any of my primes (135/2, 85, 35) if lighting is bad - which it usually is....
Need to decide soon on the value of getting the loaner pro camcorder or learning the 5d3 (or 7d/1d), but really hoping to have quickest learning curve to achieve least. amateurish looking video (despite the fact I am an amateur at video )
Links to readable resources on the basics of DSLR videos is appreciated, I read the Canon stuff, but am hungry for knowledge outside of the marketing....