Hello, been lurking here for a while now.
We're looking at getting a 3500/4200/gransport in the next 6-8 months, so thought I'd join up for some advice
Currently got an Alfa GT diseasel and GTV V6, and know quite a few of the alfaowner crowd
Its strange to see this trail time and time again. I too went 3.2GTV to 3200 then GS and also have a Alfa GT JTD as my workhorse.
I am sure you will get lots advice below, but my summary is the 3200 is more of an animal but will cost more, the 4200 is bullet proof, and has a great, but more progressive engine. The Gransport is the pick of the bunch but you are looking £24k upwards for a decent example. Get an independant check and if the 3200 you go for have the engine endfloat measured, clutch stiffness check (I would personally go for the Auto if having one again) watch the oil gauge, pressure should be hard over on 5 bar when cold, when hot, idle should be 2.5 or higher and again hard over on 5 bar when revved above 2k rpm.
You can get an idea of endfloat from the oil gauge but the gauge senders are always failing so it difficult to gauge. The manuals tend to suffer from the endfloat issues. A quick check is with the bonnet up, get someone to pump the clutch with you watching the front lower crank pulley for movement. The 3200's do rust in the rear arches and around the rear lights and lower boot lip. If I were you, I would try and buy from an enthusiast rather than a dealer.
Oil in these cars is critical and should only be the correct Selina Racing 10w60. Cam belts are every 3 years, rear chains (engine out) on mileage at about 65k miles. Radiators leak, check the top hose for cracked flange and water running down the side (usually as a result of a cambelt change where the engineer has not removed the rad, rather forcing it out of the way) and the fly by wire throttle system is dicky, if its been upgraded to the contactless system, you should not have any issues. Check for ERROR lights this will the problems with the actuators on the active suspension or seized shocks, all very expensive.
Brakes and recent clutch will save you alot, plus if its running a standard exhaust, the rear cans rot out. If it has an aftermarket system on it, dont be concerned, this is a good thing. Drivers seat bolsters do wear, they can be simply repaired. Electrical gremlins are also common, check everything works, the aircon system especially. The clutch on the pump should ping on and you should get ice cold air.
Sounds like a nightmare, well no, just buy the right car and you will be fine. Anyone on here local to you will be happy to go with you and inspect the car for you, myself included.
Oh, and welcome the marque, its a hard one to shake once you get the bug.