Hi there. I'll have a set of 5x120 PCD ones please.
I buy and sell 2nd hand alloy wheels (about 10-15 sets a week) so I feel I can contribute a little to this as to what PCD is preferable. It all depends on two things: your budget, and the weight you carry
I'm going for the 5x120 option as I have found that BMW wheels are dirt cheap, I've bought 16s for £40 a set and even Land Rover/Range Rover/X5 18s for about £100 as they all want 22s, also there are cheap BBS's available off the BMWs and BMW drivers just don't seem to like to buy aftermarket wheels (they go mad for genuine 18s tho) so 17s and 18s can be had for less than £100, however the Land Rover wheels are going to be the ones with the highest weight rating. N.B. The 3-series BMW has an offset of around 45mm so keeps the wheels tight in, but 5-6-7-series has an offset of 15-20mm, worth bearing in mind as they'd stick out an extra inch.
5x112 wheels can also be found cheaply, no one wants the standard 16s on an Audi A4/A6 or Merc or aftermarket 16s or 17s, BUT larger wheels e.g. 18s comand quite strong money as they're quite rare as standard fit, if they say AMG on them every Vito/Merc owner wants them, if they say BBS, Audi, VW, Bentley then Audi/VW/Transporter boys go mad for em! BUT as they do fit Transporter and Vito Vans there is a large selection of new aftermarket commercial alloy wheels that have a high load rating, but then you're spending mega money. Most 5x112 wheels have an offset around the 30-40mm mark.
So, 5x120 cheap, good selection of nice second hand wheels, decent load rating on Land Rover/Range Rover/X5 wheels wheels, few, if any aftermarket comercial wheels available new or secondhand.
5x112 cheap if undesireable, reasonable selection of secondhand wheels, large selection of new comercial alloys ££££.
This is only meant to be a rough guide, if anyone has any further questions I'll be happy to help if I can. Cheers, Chris