Balance shaft belt failure into TB failure 2.0 TS

[IAmTheBread]

Hi all,

This is my first post here so I apologise if it's in the wrong section

I'm sure this has possibly been brought up before, however I unfortunately haven't come across any information regarding this yet.
I have a 1999 156 with the 2.0TS manual on 140XXX kms. I bought it with verbal confirmation that the timing belt had been replaced approximately 2 years ago (from todays date) however I never got around to visually confirming that as I was driving it with my other car in pieces at the time. Unfortunately I have learned a harsh lesson... it seems like the timing belt was changed at the correct interval, however the balance shaft belt was not 
The balance shaft belt snapped and got caught in the timing belt, pulled around the cam sprockets and bent at a minimum, all of the exhaust valves, however the timing belt itself did not snap.

I've bought a new full timing kit from Gates, and the timing tools required.
My question now is whether I should look at replacing valves or the whole head, I understand that the valves are probably not the economically smartest option and this is not something I've ever previously attempted but I do enjoy taking things apart to learn how they work. What is my likelihood that the intake cams are also bent? Seemed to have skipped 1-2 teeth on that side.

If an entire replacement head is far and away a much better option, what should I look for in the replacement head that I buy? I'd imagine any visible wear on cam lobes, any sludge buildup

Final query, given the BS belt was pulled behind the exhaust camshaft (had to yank it out from there), is it highly likely that I've f-ed up the cam sensor?

Thankful for any advice/recommendations/criticism, doing my best to learn as a young man currently driving my Peugeot, but missing my Alfa more and more by the day... 

Kind regards,
Coen
Sydney suburbs