In talking about the size of a flag, it's best to talk about the ratios. For example, the one I linked above is a standard 2:3 flag. I edited the above flag to make a 1:2 flag, which is also fairly common, but a bit longer. Pick any flag ratio you desire, then tell me which one to do.
Longer flag (1:2 ratio) with smaller circle (let me know if circle is too small or other modifications): http://i.imgur.com/bTBmu1N.png
Imperial banner (2:3 ratio) (let me know if you want any modifications): http://i.imgur.com/YJMYt3Z.png
Naval flag (2:3 ratio) (let me know if you want any modifications): http://i.imgur.com/b8zEuT5.png
If you're going to come back for more requests, please telegram me. Seeing as I'm the one with the original flag documents, it might be easier for me to do it as opposed to someone else, but I will be very busy this weekend so I won't be monitoring this thread.