Doesn't look anything at all like a planiceps... the Planiceps is alot more slender and has a head to tail stripe pattern not a tiger stripe pattern. Attached pic at the bottom to dismiss any confusion.
Feeder rosy reds, goldfish, hikari predator sinking pellets, shrimp pellets and krill all work good for that size. I've got 2 baby tiger shovelnose right now in the 240 both doing fine on those foods. They get huge though close to 4ft, heres a pic of one of my babies about 5" and a 3-3.5 footer at an aquarium in Italy ~Trent
Pretty hard to come by, the price is reasonable though just you don't see them in the trade that often, sharkaquarium and anthonys both have them on occasion but the last one I saw was on aquabid and was to big for my tank
the very first pic is a Pseudoplatystoma Fasciatum, the most common tiger shovelnose capable of 5ft, there is also another one which is Pseudoplatystoma Tigrinum which has slightly different patterning and is chunkier to my knowledge and are rarer than fasciatum in the UK. then there is Pseudoplatystoma Coruscans which is the same as the other two mentioned before but when bigger they develop stripes instead of spots and i have only ever seen them listed on importers lists once. then there is Sorubimichthys Planiceps, which get 6 ft or more and are very slim and long cats. they have a brown speckled top and white middle and black at the bottom these are fairly hard to get hold of in the uk becuase no one can house ethem properly. Sorubim Lima is prob the most common shovelnose which reaches 20 inch on average and are black to brown and the upper lip is longer than the bottom. next there is the Brachyplatystoma family which there is Juruense (the most common) and there are a few others but i am not sure of spelling. then probably the most sought after are the Merodontotus Tigrinus which reach 24" - 30" and have possible the best markings and biggest price LOL thats a rough guide lol