Considering a Defender or Series II or III. Autobox / Engine conversion options

My wife has always hankered after a Defender or possibly a series II or III but she only has an automatic gearbox license. I used to restore cars about 25 years ago and am a pretty decent welder, what conversions have been done/recommended to use an Auto box? Not looking to spend a packet on one so probably will be going for a project etc and I am not interested in anything that will drink petrol like a V8 and would prefer a petrol rather than diesel if possible...........Many thanks for any replies.

Tdi or td5 with discovery box

Doing that to a Series would be a shame - and financial suicide. I'm anti-diesel too and would be looking at mating anything with 150hp-ish to an autobox from a Discovery. So many good little engines out there to choose from.

Buy a Defender, there are Series around with autoboxes, they occasionally come up on e-bay and sit around for ages. The problem is the gear lever comes up in the middle of the centre seat and so much has to be modified.