Hi, Kayla, I know a little about the stores in the Iselin/Edison area. They are mostly Indian stores, there is a mall which has a dozen or so desi designer stores. The address is 1710 Oak Tree Road, Edison, & is called The Mall at Oak Tree.
There is a Ritu Kumar store there that has some very nice things, I have a mehndi green & pink suit from them with beautiful work. Its pricey, but they have sales very often on in-store stock & they take custom orders if you have the time. There is also a Satya Paul store (they have suits & lenghas as well as sarees) & a lot of other stores for designers that I didn't know.
There is a Sheetal Design Studio (Hemant Travedi's boutique) further up Oak Tree Road - its very, very pricey & I don't care for the designs (they are very Bollywood gaudy with skimpy blouses!), but nearby is a boutique called The Origin, where you can custom order lenghas, suits etc & the prices are quite reasonable given the quality (they have two stores, you want the smaller one off the main road, not the one next to Sheetal, the little store is the original & has a better selection). The quality of silk & work is very nice, my friend ordered a lengha for her engagement from them, it was a beautiful burnt orange color, with cream & gold work & I have a suit I ordered from them - its dark navy blue heavy silk with gold kaam, I selected the weight & quality & color of silk, style of the kurta etc, & they have samples of kaam for you to view (you can even pick what shade of gold you want for the kaam) & every thing can be customized to your size. They have samples of the various styles so you can get an approximate idea & then decide how much customization you want (this color, that sleeve, that shirt style & so on). A custom order takes about 6 weeks if I remember correctly. They do have items you can try on & purchase there as well & a tailor can come in to make alterations, but you don't have the same selection & the fit isn't as perfect.
There are a lot of stores along Oak Tree (not just clothes, jewelers too - Raj Jewelers has some beautiful things) & its worth taking an afternoon to visit & see the selection to get ideas of what s available.
Hope that helps!