If I would have found one 93-95 model with original 1KZ I would have gone for it rather than my 99 surf, as its way cheaper than 3rd gen surf.
You must get the one with original 1KZ its serial no on vin plate would start from KZN130 rather than LN130, most of them are swapped from there 2LTE to 1KZ but unless you change its transmission and differentials you wont be able to get the optimum output, so stay away from swapped ones.
Regarding ride comfort I dont have its experience and you have to try it yourself.
Here is a link to one of these:
Used Toyota Surf 1994 Car for sale in Islamabad - 1326038 | PakWheels
I think he is asking little bit higher price and if its really pristine it should be around 13.
Toyota parts are not an issue at all.
But rest assured to change all of its oils (engine, transmission, differentials, transfer box) filters (diesel, air) and belts (timing belt, bearing, tensioner, generator, radiator), total cost would be around 40k or if you got its complete history than you may avoid.