Which name do you like better?
Last name is single syllable.
(I don’t personally like the nickname [name_m]Ozzy[/name_m] for [name_m]Oscar[/name_m], but know [name_u]Oliver[/name_u] is very popular)
I prefer [name_m]Oscar[/name_m], although I’ve always thought [name_u]Oliver[/name_u] is a lovely name too, just very popular.
[name_m]Ozzy[/name_m] isn’t commonly (if at all) used as a nickname for [name_m]Oscar[/name_m] here (Australia) but I know it is in [name_u]America[/name_u]. I wouldn’t let that stop you from using it though, it’s a great name. And [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u] sounds fantastic!
[name_m]Oscar[/name_m] [name_u]Sullivan[/name_u].
I personally prefer I [name_u]Oliver[/name_u] by far and I personally don’t think that [name_m]Oscar[/name_m] matches very well with [name_u]Sullivan[/name_u]
I prefer [name_m]Oscar[/name_m] with [name_u]Sullivan[/name_u]. [name_u]Oliver[/name_u] [name_u]Sullivan[/name_u] scrapes by through the skin of its teeth in terms of not being an overload of ‘l’ and ‘v’ sounds and I don’t think [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u] sounds that bad. It actually sounds quite handsome. Although I generally support having longer names with short surnames to give the full name more substance, I don’t think a single-syllable surname would be an obstacle form naming a child [name_m]Oscar[/name_m]. Though, the one drawback would be the nickname. I’m not a fan of [name_m]Ozzy[/name_m] either and [name_m]Oscar[/name_m] isn’t exactly a name with much nickname potential beyond that. I personally think [name_m]Oscar[/name_m] doesn’t need a nickname, but a boy named [name_m]Oscar[/name_m] may get called [name_m]Ozzy[/name_m] at some point in his life.
I prefer [name_u]Oliver[/name_u] in general, but [name_u]Oliver[/name_u] [name_u]Sullivan[/name_u] doesn’t flow as well for me due to the repeated ‘li’ sounds – so regarding that, my vote goes to [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u].
[name_m]Oscar[/name_m] is an handsome name, and [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u] sounds nicer imo 
I don’t think you can go wrong with either one, but if I had to choose, I’d go with [name_m]Oscar[/name_m] 
[name_m]Oscar[/name_m] Sullvian is beautiful!!
I love both names, but dislike [name_u]Ollie[/name_u], so would choose [name_m]Oscar[/name_m]. I know an [name_m]Oscar[/name_m] who has never, to my knowledge, been called [name_m]Ozzy[/name_m].
Both names are wonderful ! I am super bias because [name_m]Oscar[/name_m] is a sentimental name for us - however [name_u]Oliver[/name_u] [name_u]Sullivan[/name_u] feels poetic and sing songy and I love how the L’s roll
Ultimately I think [name_u]Oliver[/name_u] would get my vote
I prefer the pairing of [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u]. [name_u]Oliver[/name_u] [name_u]Sullivan[/name_u] is alot of L’s.
[name_m]Oscar[/name_m]
[name_m]Oscar[/name_m]!
Also prefer [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u], the flow is just lovely. I think you could find another nickname for [name_m]Oscar[/name_m] but I also think you may not mind Oz/Ozzy as much in case you use it.
I find people usually end up calling their babies very natural nicknames (unless the go exclusively by their nicknames) and don’t dislike them as much as they previously thought so.
That is unless they have a negative connotation, obviously.
[name_m]Oscar[/name_m]!
[name_m]Oscar[/name_m] [name_u]Sullivan[/name_u].
[name_u]Oliver[/name_u] is very over done. [name_m]Oscar[/name_m] is charming.
I don’t see anything wrong with the flow myself?
I prefer [name_u]Oliver[/name_u] in general, but I prefer [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u] in combination. [name_u]Oliver[/name_u] [name_u]Sullivan[/name_u] is a little tongue-twister-ish.
I prefer [name_m]Oscar[/name_m] but I like it with a k instead of a c.
I like [name_u]Oliver[/name_u] much better but it doesn’t flow with [name_u]Sullivan[/name_u]. [name_m]Oscar[/name_m] [name_u]Sullivan[/name_u] is better [as a combo]
I don’t particularly love either of them, but if I had to choose between them I prefer [name_u]Oliver[/name_u]. [name_m]Oscar[/name_m] to me reminds me of [name_m]Oscar[/name_m] the Grouch, and sounds like an old man name.