Waking up every morning with tightness in your neck or back is not okay. It may be because of the sleeping positions you are in. Unsupported sleeping for 6-7 hours at night may continue to cause strain in the body where your back muscles have to work hard to get your body back to neutral. The tightness generally is from those specific muscles which are overworking in a position to find the neutral for your body against gravity.

The goal while sleeping on the back is to keep the spine in neutral so there is no added strain on the body. Gravity still works on your system while you are asleep so we need to minimize the effects of gravity by adding extra pillows so all the muscles and joints in the body can relax while you lay in a particular position. Generally, laying on the back with the legs stretched out will increase the normal curvature in the small of your back. That happens because the psoas muscle that is attached to the front of the spine and the discs in the lower thoracic and lumbar segments to the hip is stretched which increases the curvature in the back. You don't need to buy any fancy props to counteract that.  Instead, use at least two pillows to support your legs as follows:

The first pillow supports the leg from the bottom of the buttocks to the knees horizontally. The second pillow goes under the first pillow from under the knees to the ankles so the knees are slightly higher than the hips. This will help relax the small of your back in to the mattress for support. The third pillow goes under your head and neck supporting up to the top of the shoulders so there is enough support for the curvature of your neck.

Pillow supports can not only prevent symptoms but also protect your spine in the long term. If the position you are sleeping in comfortable, it will reduce the number of tossing and turning in the night and provide better sleep.