Best classic muscle car for big/tall fellow?

[Mini 9]

Going to Mecum auction tomorrow. Friend is 340 or more pounds. 6' and a few. Usually drives full sized trucks. Trying to get him to spend is money. Obviously convertibles have the most headroom, but aside from that, any cars good for large fellows?

http://www.mecum.com/auctions/top_picks...._ID=SC0514

and how would one EVER know if they like how any auction car rides/drives?