The standard bluetooth opiton on cars with production date later than July 2014 has capabilities of both making phone calls, listening to music via bluetooth. in addition, if you have an apple product, it also supports voice control (Siri)
I strongly recommend getting BMW Professional Multimedia option (NBT or NBT EVO depending on model year). It enables you to watch dvd, navigation, BMW Apps, CarPlay, Mirror Link. it has built-in apps like spotify etc.
Adaptive suspension is a quite expensive option in where I live, so I decided to pass on that one. As far as I know front suspension on 1 series is a double-wishbone. Which is quite adequate for sharp bends. It is also quite hard to slip the end of a 1 series due to short driveshaft/axle.
if you are planning to get a 1 series, harman kardon system consists of 12 speakers and 360 watt amplifier. it is a bit weaker than the one they put on 3 series (16 speakers + 600 watt amp)
The difference between HI-FI kit and harman on 1 series is that harman has extra 2 tweeters on doors and a loudspeaker behind dash.
I had HI-FI on my previous car, and the newer one has harman. I can tell mid range tones are great compared to HI-FI. other than that if you are not much into instrumental music, you will be good with HI-FI.
Cruise control is easy to retrofit. it's just 2 buttons on your driving wheel. easy to mount, easy to code. The forum will help on that if you wish.
Good luck
