Understand your question now, you are talking about a new with a $12k diesel option. Sorry, I'm just a bit slow.
Honestly, I would think long and hard before purchasing a GM conversion with IFS, I just think it's too much of a weak link, especially on a SMB riding with 10k# everyday. I understand Quigley is now lifting the IFS vans, which I do not think is optimal and maybe even less durable than stock height.
OTOH, if you can find a co. to do a Dana 60 front end on a GM (that's the setup mine has), I think it's tough to beat.