After finding the idea of the idea of Iron Hands Drop Pods (it will not die) amusing I double checked the rules for Unbound.
Unbound says you can use whatever ‘Units’ from your collection you want. So yes, you can use dedicated transports but they will come with their contents. The dedicated transport can not carry anyone else when it deploys but the unit it was selected with RB pg 82. Deploying from orbit in this case.
So your choice is unbound taking as many drop pods as you want from the fast attack section of the Space Wolf or Blood Angels codex’s …
Or
Taking a combined (or some other) formation from Blood Angels or Space Wolves.
I was looking at
Space Wolf HQ + 2 Blood Claw units (covering area of Sisters weakness) deploying in drop pods with an extra 3 fast attack drop pods for Sisters with Heavy Support been Deathstorm drop pods.
But then I read about
The Flesh Tearers Strike Force from Shield of Baal: Exterminatus. This apparently allows you to have Blood Angel HQ + Troop Unit + 6 (yes 6) Fast Attack choices which of course could be drop pods giving a ride for 5 units of Sisters
Not confirmed that this formation exists so that will need to be checked out.