Im based in Derbyshire too. There arent really many venues in Derbyshire, though the surround counties are dont take long to get to. The closest ones I would say are; Hargate, Field house, Markfield, Westfield park. But for a full list you can visit the BJSA website click on shows, then show...
At the yard I currently stable my horse I pay £75 a week full livery that includes; one bale of shavings a week (though normally have more), hay/hayledge , primary feed i.e. nuts/chop. And use of all facilities.
Last year when I kept my horse on a professional show jumping yard, I paid £100 a...
I'd make sure you are going well at home practice your distance's etc... esp with the 13.2 to make sure he can cope with the strides, I don't really think it will be to much of a problem in the lower classes such as British Novice as a pony can pretty much get themselves out of trouble. Though...