for the size thing, there are plenty of other posts on a similar or the same subject, i suggest you read them - but basicly you've got to make the decision - if you buy 60s or 70s, you'll probably get your technique better, but then will need to upgrade soon so its wots cheapest, or wots going to make you a better bocker...
i don't know if there are may people in your area though, i think there may be a couple on the pro-jump map you could check out, but some of those people don't always stick with it - else i know there are some further south in NE England who would be happy to accept you - most bockers will