Sentra is an older 90's design. I think the only way it fits you is because being a C-segment car when you push the seat all the way back and angle the recline, might be okay when you first sit in and might be okay when you drive to work but when you go outstation it is going to hurt your lower back.

2010 Nissan Latio 1.8 - would be a better choice for you as it is also a C-segment but newer design thus higher roof enables you to sit with a better posture, instead of half way laying down to sleep. In terms of power it isn't that bad either with a 1800cc engine, I don't think there are any 1800cc c-segments at this age and price for a japanese car which is easy to find parts and they are cheap. You can get much more powerful and better conti but the maintenance is a killer, this car is quite a good balance for your needs. Shop around as Nissan is one of the few that still provides a manual gearbox for their mid range models you might be able to find a manual or 1600cc variant if you want but I think this top range model is the one you need.