I've used Neopan 1600 a few times, exposed around 800 and developed in Microphen. I used 1+1 for 5min. I think it's a good film for 640-800, but not 1600.
I've used TMax3200 exposed at 800 to 1000 and developed in TMax developer according to instructions for that speed (which gives not much contrast). That suited my choice of subject, but I think that it's too grainy for a subject which is small in the frame (e.g. stage photos with small faces etc)
I've taken Delta 3200 thru x ray machines many a time with no problems. If using it with DDX you'll probably need to up the temp/use a stronger solution as otherwise the negs can be a bit thin.
I don't see why you shouldn't stick with what you are already using. A one stop push is no big deal. You should already have accurate times for these films so you will have a good idea of what time you need for a one stop push.
Switching to a different film for just one stop seems a bit over the top, unless that is of course you just fancy a change and something new.