Get the '95 I would say...the 91 has auto seatbelts, but the miles are almost ideal for a car that age. The 95 will have dual airbags and those may come in handy some day (though hopefully not). However, the G20 is Consumer Reports' number one rated car for reliability (80% above avg.) and you will be well off with either.
See if you can get maintenance records for both and be sure to get a CarFax report for both. Those prices are darned good but the '95 is a better value if you have to resell.
Nissan makes darned solid cars and my Sentra got up to 186k with few problems before it was totaled.