Advice on HU upgrade please

So I've decided I want to switch out my head unit...I've been reading a ton of stuff on TW, Crutchfield etc. and I am overwhelmed...
Hoping some folks on here might help me decide.

Currently I have a panasonic HU. I have upgraded all my speakers with Alpine Components with Mr Marv mounts, and I have a Planet Audio amp installed to drive everything, including a pioneer bandpass sub that fits nicely behind the passenger seat of my access cab,

I want a new touchscreen DVD receiver with bluetooth etc...yadayada... that I can use with the amp and speakers already installed.
Budget: lets say 800 bucks (Canadian) installed and including all adapters and dash kits etc

Sooo...

I'm thinking maybe get a Pioneer AVH-X2700BS, which would be about 400 bucks, leaving some cash to get it installed so I don't f#@* it up.

Questions:

1-Will this unit work with the bypass trick I read about on here somewhere? (holding finger on screen trick?) I would rather not fart around with the park brake.
2-Could I add navigation later with this unit?
3-does anyone have one and want to share their thoughts or pics?
4-any other recommendations for a better plan? (I have an iphone4s, ipod, and Samsung android 10.1 tablet...)

Thanks TW!

Tom