Hi, I’m new to the forum
Currently in the process of selling my M240i and I’m looking to replace it with a 5dr GTI...
Welcome C3

Why would you change a 240i for a GTI out of interest?
I’ve got a tiny bit of experience with Golfs so I’ll throw in my tuppence worth.
Options wise, I’d not get hung up on them. Go for the best condition latest model car you can possibly afford.
The later the car the better the standard kit as a non scientific rule of thumb.
Personally I’d sell all the family silver and live off Tesco basic food in order to try and find a way into a very late car. Where there’s a will there’s a way.
I used to be a Dynaudio sceptic but am now a convert.
BUT few cars have the option and the standard kit is ok if you’re not an audiophile fusspot.
There’s a Helix subwoofer that’s available from VW which would do a good job of upgrading the standard kit if you find a car you otherwise love which doesn’t have Dynaudio as standard.
The Performance Pack makes the GTI.
The bigger brakes are useful when you need them most, plus they’re nice and progressive to use.
The diff takes a bit of learning but is really good, it rids the car of understeer and eliminates wheelspin coming off greasy roundabouts or out of tight country road corners.
Ignore the extra headline power in the early models, it’s just there to help justify the extra cost on the pre facelift cars but there are more significant hardware differences on the 245 bhp model.
DCC is a ‘nice to have’ but totally unnecessary. The cars are fine without it.
In fact I’m probably a lone voice but I really don’t rate DCC.
Infotainment discussions bore me senseless so I’ll skip that

Again, if you can possibly scrape to a car with the later MIBIII I’d recommend it. CarPlay is good but is fairly ubiquitous in most modern cars(?)
Wheels, I love wheels.
Santiagos look sexy but are a pain in the bum to clean.
Brescias are nice.
If the car has standard 18’s it’s not that expensive to get half decent quality replicas in 19” if you feel you need them.
I’ve had four(?) manual mk7’s and the gearboxes were all good except for my 2013 GTI PP which would occasionally be a bit obstinate.
I’m now in a DSG.
I’d been curious about DSG for years so bit the bullet.
Now I’m one of those people that likes to buy something and lit just to work.
I don’t need 3000 programs on my washing machine, I don’t like my dishwasher to have unfathomable sequences of lights that may or may not tell me it’s going to run a program that’ll be finished before next Xmas.
I wasn’t one of those kids that sat piddling around with computers learning all the different ways you could find “shortcuts” into programs and sub-programs. I like to switch a computer on and be able to do exactly what I need to do without having to spend 15 minutes googling what comes as second nature to a nerd.
DSG gearboxes are utopia for nerds.
There are many ways of achieving exactly the same thing, be it paddles, throttle pedal kick-down switches, various directions of angling the gear lever and so forth.

Seriously, all you need to do is leave it in D, then when you want to go very fast just pull the lever backwards and the car will make progress far quicker than my brain can process. Then when you want to return your pupils to a normal size and decrease your blood pressure just pull it backwards again and calmness and serenity will be restored.
So yeah, get a DSG.
Or a manual, they’re both good.
Costs, well service costs are on a par with any other model of Golf except replacements of the bigger discs or extra VAQ servicing.
Oh, and I’d recommend getting an R not a GTI, it’s a much better car.
But the GTI is a great car.