Any suitable telescopic aerial will fit, the aerial doesn't come anywhere near the tyre as the steel wheel-arch separates the two.
In 20-years of owning my 90 I think have only ever had three aerials, the most recent of these I only fitted a few weeks ago as the old one snapped as I was pushing it down. As long as it is SS construction (I believe they all are?) then you shouldn't have any issues with corrosion. That said, after washing I always dribble a spot of oil down the aerial to keep it clean and working correctly.
When replacing my first aerial many years ago I fitted an aerial flylead extension between the back of the radio and the underbonnet area, that way there is no need to go fishing around behind the dash or removing the radio, makes replacing the aerial a simple 5-minute operation.