dirt bike purchase

Anyone out there got a more modern history with these, my history stopped 15 years ago at the age of 29 ish, used to pony express and ironman......anything and everythig trail ride for about 18 years.

I am looking for a full sized dirt bike, no need for rego but still can be one of those models, must be light and full sized rims and I guess around 2006 to hit my budget...of which I dont know what it is yet also would prefer air cooled but I recognise time has moved on and I might need to consider more complicated engines for simple trail riding.

Only ever going to be 'oldie' cruising tracks these days with/behind my daughter on her 50cc.

Oh it might also get my wife on it every now and then if she decides ( biggest reason for lightness).

Trying hard to nail down some models...fast 250cc + options are way too testorone for me now as I might just be dumb enought try and use them properly :)

any ideas?