I agree that a brown tie is not the best choice here. I think that suit is the star, any time you wear it, so stick to a basic navy tie, with a simple pattern. For some reason I can't picture a solid navy tie working, but I could be wrong. The suit itself is absolutely great. Is the bunching on those pants caused by poster, or are they maybe too long?
The fit of the jacket is very good, but the pants appear a bit full at the bottom, and might benefit from the addition of cuffs to impart some weight (if its not too late). The suit pattern is, apparently, fairly typical Isaia in that the scale is kind of in-between: neither bold enough to provide real impact, nor discreet enough to recede from a distance, imparting a kind of checkerboard effect. I know; I have one, albeit in blue, and so did Rudals/Noodles before he returned it to his pals at NM. I don't hate it, but neither do I love it. The jacket fit puts it in the plus column for me though (on second glance, are the sleeves perhaps a touch on the short side?)