You have a lot of research you need to do. Both the BIowave and the Ultima IIs are filters that need purging (usually tank water). So it is especially handy to have a drain in close proximity to the filter. (handy, but not a requirement) The purging, therefore self-cleaning aspect, IMO, is the true beauty of these filters. Both of these filters are usually used in large pond systems.
There are different models of Ultima IIs starting with Ultima II 2000 (supports 1,000=2,000 gallons) going up to Ultima II 100,000 which supports bodies of water 60,000 - 100,000 gallons. Each filter has a recommended optimal flow rate. So for whatever filter you select, you need to choose a pump that would perform at the optimal flow rate. For instance, the optimal flow rate of the Ultima II 2000 is 2,000 gph at 10' head. Direct self-priming pumps are recommended. Minimum flow rate 1,000 gph; maximum flow rate 2,500 gph. So you would select a pump with the recommended optimal flow rate. The Hammerhead would be WAY too big at 4,800 gph at 10' head. You don't have to figure it out on your own, if you don't like doing so. If you are interested in any filter, call the company up and ask for their pump recommendations. I find this stuff kind of fun and like to select and choose filters, UV sterilizers and pumps where the pump flow rate and recommended flow rates for the filter and UV sterilizer match.,
But back to what I wrote earlier, knowing what you are going to do for filtration, and where it is going to go, will help you decide your stand height. In my case, we have an in-wall tank, so putting filtration under the stand was not necessary, and we got by with the low 2 ft stand. All our filtration will be behind or on the sides of the tank.
