WDYT of this boy name?

Hazel08

Foster William.

Not sure if I love it myself yet, but we tend to like the not super popular names.  Other choices are Oliver or August.

MrsTeague

I like your other two names better. My best friend had a dog named Foster.

lisa5201

Not terrible, but I LOVE August.

That would be my first choice 

lovemytwoboys

I don't really like Foster, but I do love August (or Augustus) with the nickname Gus. I think it is adorable, but my DH would have nothing to do with it.

cabo_kate

Wow, Oliver and August are so gorgeous, Foster just totally seems out of left field. I don't like it at all. Way too surnamey and it also sounds like a verb, as in "to foster".

Your other choices are miles better. 

ToBeMrsT

I don't really like Foster.

LMS05

I don't like Foster. Oliver is a lot better. 

elyselowe

I like Foster but not with William. I also like Oliver.

magsugar13

I like William and August

I do not like Foster or Oliver

j_luvs_r

I think Foster could work as a mn, but I'm not a fan of it as a fn.

I love Oliver & August.  They both sound great with William as a mn, but these are also options:

William Foster

Oliver Foster

Oliver August

August Foster

August Oliver

Good luck!

Soon2BMrsN

I don't think it flows very well.  LOVE Oliver.  What about Oliver William?

CAM718

My freind also has a dog named Foster, and the dog was named after the beer, not a good name for a child IMO, I like Oliver and August though.

bb80

i personally think of beer when i hear Foster's, i prefer oliver but that's jmo

Smores730

I prefer your other choices of Oliver and August. I keep thinking of foster kid and it then it seems weird. Here's my son Foster, but he's not a foster kid :-/