I used film hangers and large deep tanks a lot back in the 70's and 80's, and they are very easy to use. Using Pyrocat shouldn't be a problem but remember once mixed it wouldn't have a long tank life. Not being familiar with the smaller tanks you thinking of I don't know their capacity, I use an older Jobo (Inversion type) now and find it's economic with Pyrocat using 1litre of dev for 6 sheets of 5x4.