Alternative to daily ibuprofen?

Chronic neck pain means there is something wrong. You should see an orthopedic doctor. It may be as simple as some exercises or it could mean a simple operation. Either is better than damaging your internal organs with pain killers

ask your doctor for an alternative

Naproxen is very effective for joint and muscle pain.

400mg is a low dose so kidney damage is highly unlikely. Ibuprofen gel, either otc or prescription strength, will provide localised pain relief with very little , approx 5%, working its way into the blood stream and through the kidneys and liver. Have you seen a specialist about your neck or seen an osteopath or chiropractor? Another oral medication that could help is Nefopam which acts like an opioid but isn't one and isn't habit forming. Anticonvulsants are used to treat chronic pain such as Pregabalin and Gabapentin as well as low dose tricyclic antidepressants such as Amitriptyline. If your neck pain is muscular then a muscle relaxant is a good option such as Tizanidine. There's also Ketamine and Lidocaine infusions, low anaesthetic patches, steroid injections the list goes on.

Try going to a chiropractor