TTR230, CRF230.
But really, the criteria is easily met, so any of that sort of bike would be fine if he finds a decent condition example for a sensible price: XL185/200, XR200, DR200, XT200, TTR250, KLX250, DR250, etc etc.
Hell, if a PW80 got his heart racing, he'll probably be happy with anything (in the short term at least).
The older 200s might be a bit limiting if he gets a bit serious, but if he's an older bloke who just wants to putt around, any of them will fit the bill beautifully.