Some people take landscape pictures with 20mm, others use 200mm (35mm equivalent). What advice do you expect here? Maybe you should spend more time thinking about what you use right now and in which way this equipment does not deliver what you need. Once you know what you need (note: not want) it becomes quite obvious what to look for. Also: what is your budget? For some $100 are peanuts, for others it's a hefty price tag. For second we have a Buy & Sell section here.
I tink u shld read up on various manual focus lens and the various mounts, if u are interested. Seems like u do not noe tat much yet, stick to conventional sony e mount lenses for now den buy on impulse. The rest of exploration can wait till u noe more abt wat u need.
Not sure about NEX... but maybe you can use a close-up lens for macro purposes, so you can stick with your kit lens for landscape and architecture purposes, slap on a close-up lens like the Raynox 250.
for the e-mount lens, it looks like you have only a single choice.
your only other option is to get a A-mount adapter
For lens(es) that you might want to use for capturing landscape photos, any lens will do for as long as it is able to meet your fov requirement that will fulfill your vision in the photo.
or you could get the LA-EA (first generation) and the SAL1118, but without the AF. that's because you can shoot manual, yet rely on the MF-Assist and MF-peaking to ensure that your subject is in focus. this would be a cheaper alternative