I'd personally stay away from the heavy holstein influence it it were me. (Unless you own interest in a feed mill)
If it were up to me I'd look into the MS cows. They tend to hold their body condition well when on grass. I know it all depends on the cow but traditionally they've done well for me. I realize you didn't mention the Ayrshire breed in the mix. If you can find one of these, that'll be the true ticket. I've got a dairyman friend in Southern Kansas who has went totally grassed based and is average good milk output on no grain at all. MS cows have a lot of the ayrshire traits and characteristics.
I'm also a jersey fan, but I have to feed mine pretty heavy if they're getting milked pretty heavy. Sometimes it don't pencil out in the black pound for pound. They do however make great nurse cows and produce some pretty rich milk to get calves going good.
I have one cow I picked up that I am not sure on the breed, I'm not sure if they do or don't have Ayrshire but I have a calf I got form them I am unsure of the breed. If it has Ayrshire in it I imagine it is a cross between that and a holstein. It is mostly dark with a few white spots and a little redish brown all over. I'll post a pic of it tomorrow and you tell me what breed you think it is.