It's not the frequency that you need to change - the frequencies are going to stay the same.

The Lyngsat 1N channels (that you found) are the ones that are going to move to 1E - and soon!

The noise figure/quality of an LNB makes no difference if there is no signal, which will most likely be the case when the 1N channels are migrated to 2E.

I have no idea if they still make the flat dishes - they were called 'squarials' if I remember correctly. If they do I very much doubt you would find one big enough for here.