I am an avid user of both clans, I will give my opinion.
Elo:
Bangers for sure but they are expensive but powerful.
cost for
Bangers in
elo: about 13k for Blaaster. another 10k for
Shann and
Shogunn and about 5-10k for the rest of your deck.
Ulu in
elo: never ever ever make a mono Ulu deck in
elo. Their good cards are
elo banned and they need at least 1 5* for playability which could potentially make it harder to make a deck.
Cost: 10k for a good half deck.
T1:
Ulu are usable but not recommended.
Cost: 100-120k
Bangers: They shine here highly recommended.
Cost: 30-35k.
T2:
Ulu: They are amazing here, Have your army of 5*s +
Wee Lee and Graks and
Ambre and you have yourself a killer deck.
Cost: 150-210k. ( a lot less when Tan Man wasn't a CR)
Bangers: Still nice to play however aren't as powerful without
Ambre compared to Ulu.
Cost: 30k (aprox)