Some years ago, I had van tyres put on my twin axle caravan. I think they were ply rated 4 or 6 ply. Just worth asking the tyre dealer if the same size and aspect ratio is available with higher ply rating. There is no such thing (technically) as a caravan tyre... just an appropriate size, type etc. So do ask...van tyres stand up to some fairly hardy use and long standing without sidewalls cracking so easily.
I have also just bought a replacement leisure battery. I seem to have to buy one every year as I don't use the caravan often and forget to take it out and charge it
Amp hour is less relevant if you always have EHU, so I opted for a 75 AH from EuroCarParts. At £62 odd it was a good price. Always search for a discount code. I used FOOTY50 and just under 40% discount.