Hi,
The GS150 suits most of your requirements. Even the CBZ X does so but as a personal choice i would prefer the GS over the CBZ. keeping pillion comfort in mind, the RTR and P180 are not very comfortable in that area. Though your fiance might want to upgrade to a more powerful bike(in comparison to what he has currently), in that case the P180 or RTR 180 would suit his liking. Take my word enthusiasts never crib about low mileage when they get decent power in return

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best of luck for your purchase and keep everyone posted on your final decision