Like with all the tackle for drop shotting the landing net wants to be nice and light, the lighter the better. I would also highly recommend getting a rubberised net.
It really does make getting snagged hooks out a damn site easier. Especially if you end up using it for pike fishing at some point in the future and get some trebles tangled up in it.
A lot of the top names now produce some nice light compact landing nets that are foldable and will clip onto your belt or luggage with ease.
This makes it easier for your travels up and down the bank in search for the perch. The length of the handle should be determined by the venue that you are targeting the perch on.
Canals and venues like an average commercial fishery you will probably get away with a smaller handle around a metre long.
For lakes and rivers with high banks and reed beds etc maybe target a telescopic handle that reaches to about 2.1 metres.