Skaw, I think I got lost in the loop here. You have a project for delivery in DVCAM. You have a PD170 now and you want a B cam (or new A cam) that'll mix well with the DV from the PD170? And you have to deliver in PAL DV 5:4?
Yes
I think Wags is suggesting that you shoot in 16:9 mode in DV and then crop to 5:4 PAL so later you'd have a 16:9 tape as stock. Which is one way to go. I suggest you test some clips to see if the loss of resolution(which results in softening) is acceptable to you.
If I understand it right, this will give me a lot of resoultion loss in the cropped files ?
Another alternative (which Wags may also be suggesting) is to shoot all in 16:9 with your new HDV camera in HDV, downconvert to DV anamorphic to match the PD170, leaving you with stock HDV tape. You can set the view finder to show the 4:3 marks onscreen or in the VF so you can frame for 4:3.
Would'nt that be the best way to do it, giving the best quality ?
"Leaving you with stock HDV tape" - would be nice 
Yep...Shoot in HDV downcovert to DV 16.9 as it comes out of the camera, crop and mix with ya 4.3.
Okey, I was hoping, that it would be possible to shoot in HDV, import in NLE as HDV, crop to 4:3, and then render as SDV. To me that sounds like the best way to avoid resoultion loss, but perhaps it's not possible ?
If I downconvert to DV 16:9, and the crop, there will be a some resoultion loss.
Unless - I am misunderstanding the whole thing 
Wags.
Could I ask you to provide me with a 5 sek. out of the camera HDV PAL clip for download ?
I don't even know what filesize it will be, but hopefully not too large....
It does not have to be anything special, just with some sharp details, nothing spectacular.
I will then "play" with this clip in Vegas7, and try and mix it with my SDV, to see what results I can expect.
What say you ?