I'm sure we've all a wish list still,
ARP is stronger and re-useable so always better,
They started selling the lightweight interference pulley (I think it's that they refer to) but can't actually fit it so really you're better off in my own opinion, sending the charger to GTT and getting them to fit their 15%, interference fit is the original factory way so no risk of charger shaft damage which does happen. Another one on here in the last week or so. FYI GTT were the original and only people producing these and fitting them.
Cams, one is the Newman PH2 which is a good fast road cam with decent idle manners and pulls from quite low and cleanly to 6k+ before tailing off, the Catcam that people talk about most is the 469 which is a rung above the PH2, it has a bit of a lumpy idle and is best used with a remap very shortly after really so will stall a fair amount until then, it pulls from a bit over 2 and is stronger than the PH2 between ~5-6 I'd say and goes on cleanly to 6.5+ before tailing off a bit. I have a Kent cam that is between those two, similar idle to the Newman PH2, a bit more hunting which is rhythmic and ideally also wants a 50-100 rpm added to avoid stalling when manoeuvring, this is very slightly weaker than the 469 around 5 but pulls from a bit lower so good in town but runs to 7+ we didn't get it to tail off when run to 7.2 and the graph was still climbing @230. I'm just about to test this again for the last 400rpm if I get round to it, I don't think there's much to gain, 3-5 maybe (the 469 gave 3).
Then there is the Newman PH3/4 which is really quite a lumpy cam you'd not necessarily get on with on the road in heavy traffic all the time, but with a proper map it will steady out and will be fun away from city centres, this will pull from nearer 3k and pull quite hard to 7+ before tailing off, this might benefit from an adjustable cam gear that is available online and you could start the cam a touch earlier if preferable or adjust it's peak etc. All engines are different and this is considered a competition cam. I'm about to fit one myself and already have one in the other car on an adjustable gear but I haven't run it yet. This would work well with my shorter final drive on track (or road) where you could chase down all sorts. (rev limiter limited!)
If your driving is mostly town and you just want to improve the spread of power and torque or don't actually like the engine revving high, as some people don't like the noise etc. then you might prefer the mild cam options, so a Newman PH1/2 for example, or Catcam 461, both similar.
On the other hand if you will be using the car as a weekend car or are happy to turn heads on the road and definitely will use the car for driving out of city centres for more than a few miles, and want a strong car for track playtime then the PH3/4 will suit you.
I can supply and fit a Newman cam of your choice outright for £320 plus bolt/seals as required or a Kent one I have here used in perfect condition for £360 plus bolt/seals, the latter is from a billet blank. If you want your charger removed and refitted I can do that for £240 plus carriage to GTT and OEM coolant plus oil kit with the car left here while it is sent away and returned for the pulley swap, then cleaned up and new BMW coolant added after the cooling system is rinsed out. If you want a new water pump you can have one fitted for no additional labour.
Cams I can probably swap while you wait fwiw.
I would advise some prevention work in regard to engine condition for the latter cam or food for thought with any big power hikes really when adding ~100hp. With a PH3/4 I would fit ARP bolts top and bottom, plus recommend a head gasket change and new thermostat, also just a fresh set of big end shells will pay dividends, before fitting them I personally would lift the pistons and at least clean and inspect them at that moment and check the small ends. You can do more if you intend to exploit the upper end of performance more like add rods or a stronger piston set. That would be involved and from £1200 plus parts, engineering ~£200, oil, and OEM filter and seals etc. I'd encourage a similar check on the head components, re-lap all valves, new seals and inspect/clean etc.
You should really add an oil cooler before running the higher performance cams if not before.
If you would like to test cams, I'll fit any Newman, Kent, or Catcam from a selection of used excellent condition camshafts available for £360 plus bolt/OEM seals which I'll buy back within 30 days for £240 plus bolt/OEM seals, or exchange for another for a further £120 and reset the 30 days. Either swap, keep, revert.
R50/R52/R53 cams are used with roller rockers, and rarely suffer wear such as with swept surface cams. You keep your displaced parts for disposal/refit/sale etc. OEM seals for the rocker cover generally accept being re-used.
Full diagnostic fault code check/clear/review or adaption reset £18 (option coding +£6)