Hi Guys,I need some suggestions. i have '12 v6 prem with shaker 500 system. i am looking to get a in-dash navigation for my stang. i read a lot of posts in forums but not able to figure it out completely. i have some questions

1. which dash kit is best suitable(metra or scosche or any other)?
2. what is the best navigation(am looking around $600 to $700)?
3.which one is compatible with sync?
4.can we retain the steering wheel controls?

i recently installed 12" JL subs and amp. does it need any further modification with this nav installation?

thanks in advance..

SRI.