PING have stopped producing G20. You may still find a shop with a black dot iron in stock, which PING could then adjust (if required) but you can no longer order a custom build.
eBay is your other option or you could go for a G25 or Tour Gorge.
american golf is where i got mine from they order it from ping directly if they still have some old stock there, only thing is mate i would suggest the new gorge wedge as the sole of the g20 is so thick its very hard to use on tight lies. i regret not getting one
I really wouldn't bother with the g20 lob wedge to be honest. The cavity is far to big you just cannot open the face. My playing partner recently upgraded to the g25's and has taken his out and got a Cleveland wedge. Great in the middle of winter on wet soggy ground but useless in the summer. If you just want a club for the distance fine but if you want to create shots etc no use at all. For the money your talking you could get a decent wedge such as md etc brand new or even some older models of other makes for te same.
I've got a vokey 60 degree wedge here but I hit my g25 sand better but its to long somtimes and I find the vokey gets me into more trouble than it gets me out of.
I thought the g25 lob might be my saving grace??
Try usedping.co.uk they are grat. I have had great service from them. I haven't seen any on their website, but give them a call, they ,ay have one and not listed it.....