Hello Sumeet,
I’m sure other will give you the pros and cons or should that be the other way around!?) of these gearboxes.
On the more general principles, you are looking to buy an eleven year old car and have set your maximum mileage requirement to an example which has covered between 4 to a maximum of 6,000 miles/a. Not very realistic in my book, and very restrictive in terms of choice.
It obviously follows that such low mileage examples will have been subjected to numerous stop/ starts, more not-up-to-temperature use , and a much higher clutch operation - i.e. not the best of operating conditions. Clutch (release bearings) will certainly suffer over time.
Cambelt and water pump schedules are not strictly in accordance to mileage, but also to time periods, irrespective of mileage - generally every 5 years.
Hope some of this might help pending more in depth comment.
Kind regards,
Gareth.