Welcome to Balg forum.
First thing, you dont need anything but your mind to evoke anything.But its fine if you would like a more ceremonial approach to your evocations.Now,I think you need to read this before anything.
Secondly,my suggestion is you should work on clairvoyance and clairaudience, these will come in handy.You might need years for it,but its better than frustrating yourself with evocations with no results.Of course there are alternative ways like using a medium (a child for example) for your evocations, or using recorders, but they might come off with some complications.
Last thing is, although your posts say you know this already,I want to point out that you will never need to summon anything for a magickal result if you know what you are doing.Magick is manipulating energy, with evocations/invocations you ask external sources help for it.But if you search psionics you can do it with your internal energy.Best of luck!