I like it.
Does it really matter if they sound similar?? I mean our girls have different names but I still manage to get them mixed up all the time.

We never discarded a name just because it sounded similar to a sibling, relative or friend. We chose their names because we liked them.

As your boys grow they will more than likely not live in each others pockets, where having similar names will be an issue. One boy may ask to use their middle name, or their nicknames.

Up to you in the end.