Firstly there are 3 sizes, get the large sized one.
Answers to your questions :
1. The max output for the large sized head is 1200/h. Its not much but works just as strong as my Seio 820, i guess because the water is pressurised at the tip due to the small arced mouth. Therefore u dont need its output to be more than 1200h/l. I am using it now directly connected to a 1400/h pump.
2. Lengthwise .... it can reach a max effective spray of about 11/2 ft
3. It can be fitted to anything easily as many adaptors are given. U can also buy pvc pipe reducer joints if your pvc is too big in diameter.