Try the Kmise necks from Amazon.
Great value for £30.
They are really slim profiles and I believe they have some sort of metal reinforcement.
Can't really go wrong for that sort of money.
https://www.amazon.co.uk/Quality-Maple-Fender-Bass-JAZZ-replacement/dp/B00SSY4MNQ/ref=sr_1_12?ie=UTF8&qid=1501835353&sr=8-12-spons&keywords=Kmise+jazz+bass+neck&psc=1