Seems to me you are working on this bass ackwards. You have fast throughput but want space efficiency and to squeeze every last drop out of not good buildings.
1. Can you consolidate into a good/or purpose built built building
2. Is speed more important than space, if so you'll have to give up one or have a mixed solution. Use one type of truck captive to aisle and one type to load trucks. Have some sort of P&D interface between them.
3. If not then Aislemaster is great solution because it does both,built like a brick shithouse out of off the shelf OEM parts and it works.
I don't sell them I do racks but I have a customer who went to them about 3 years ago and loves them. A lot of these machines are as delicate as Ferrari's (Bendi waiting for parts from UK) but this thing is like a rock crawling jeep.