Pleasant weather will be there in april....and most of the snow covered roads of sikkim will be open....so u can visit almost all places of north sikkim and nathula pass....i visited in march....
food options 1)food court,m.g. marg
2)Baker's cafe,m.g. marg
3) Rolls house,m.g. marg(best for momos and rolls)
4)D101sa plaza,near m.g. marg
there are many small restaurants for local food around M.G. Marg.....food in gangtok is cheaper....dont worry !!