Fitting a Highline system to my car

[finnjb]

Hi guys, I recently purchased a Highline head unit and a factory CD changer for my 75 .I know the CD changer will fit as I have the wiring for it still in the glovebox so one of the previous owners must have removed it. I know people are going to go "why not use a modern system" or "why not leave it as it is" and I have a very good reason for this: I want optional extras but anything new is horrible and bad. ��

Anyway I was wondering if anyone knows if it'll power up and still play my cassettes/regular radio for my dad who drives it fairly often as I'm still not even old enough to drive on my provisional... I've heard you can also get
1) A digital TV tuner for these, so the TV will work again
2) A newer sat nav disc to put in the sat nav system


If anyone knows where to get a good one of either of these or has any experience with them please let me know!

If anyone has a sat nav box or any of the aerials needed for one that they'd like to sell me then that would also be great! ��