You raise an excellent question which doesn't have an automatic "this one is better" response. Here are some of the pros and cons of each option. I recommend that you work with a professional insurance agent or financial planner to help you decide which is better for you.
At your age, a $300,000 whole-life insurance policy is probably less expensive than $300,000 worth of long-term care insurance. Whole-life insurance premiums are guaranteed to stay level for life. On the other hand, long-term care insurance premiums continue to rise dramatically, especially if the policy has inflationary increases built into the coverage.
Life insurance will definitely pay off because -- face it -- we all die. Long-term care insurance probably will pay off for at least one of you, though it's not a 100 percent certainty that either of you will need long-term care.
Through the federal Medicaid program, the government will pay for long-term care once you spend down your assets to poverty levels. But government provides no benefits upon death, other than Social Security benefits that can continue for a survivor.
If the government pays for your long-term care costs, it can come after your remaining assets upon your death. Life insurance proceeds, payable to a designated beneficiary, are exempt from government attachment.
Life insurance provides no immediate benefits to help defray the costs of long-term care, unless you have a policy that allows you to tap your death benefits early. Long-term care insurance pays for your long-term care costs as they are incurred. If you choose benefits correctly, long-term care insurance pays for care anywhere: assisted living, at home or at a nursing home.
Life insurance provides no inflation benefit. That means $300,000 of coverage purchased today when you're 65 will pay $300,000, 25 years from now, if that's when you die. But $300,000 worth of long-term care insurance purchased today at age 65 with a 3 percent inflation rider will pay out up to $500,000 at age 85, if that's when you need long-term care.
I hope this is helpful to you.