Manbat are very good value and stock everything. They are wholesalers to the trade but have several depots around the country that have trade counters that sell to the public. Their own brand is Numax, but I always buy Varta (4 years warranty, but have never had a problem), but I have my suspicions that their own brand is also made by Varta?. Bought a Varta battery for a Landrover Discovery TD5 last week, think if was £65 + vat, less another £5 as I gave the old unit in for recycling.
I have used them for years. I'm not employed or linked to them. Don't think they do mail order, but they do have a website.