Mickey, have done some research. First some figures
The secondary admission booklet for Essex shows the following figures:
The first column is the number of applicants. The second column is the number of available places.
Chelmsford Girls 609 120
Chelmer Valley 484 185
John Payne 389 180
Moulsham 717 268
You can see that the number of applicants for each school significantly outweighs the number of places. Last year, the last applicant gaining a place at Chelmer Valley came under admissions criteria 4 for that school. For this school you may therefore have a chance of admission, criteria 4 being "other children". However, it would depend how far from the catchment area you are, because it is likely that not all children from criteria 4 were admitted, those living closer (as the crow flys) being given a higher priority.
The same situation as above applies to Moulsham.
As far as John Payne is concerned, you may as well forget this school unless you are catholic. If you are a catholic and preferably practicing, then you will almost certainly gain a place.
Therefore, the best that can be said is that you stand some chance of admission to these schools but, as you live outside the catchment areas, there is a chance that you will be allocated to none of them and end up being given the nearest school with spaces available. It is for this reason that applicants are always advised to put down their catchment school.
It might be beneficial to ask the LEA the following question:
"What was the exact distance school to home, of the last person admitted to school *** for the last two years. This would give you some idea of what your chances are.
Another of your questions is related to practice papers. There are loads available and the more practice the better. The English is comprehension and is almost almost always a bit of a nightmare.
Anyway, if you require any further assistance, please feel free to ask.