Second, I would like to try a dildo with my wife to take performance pressure off me. There are dozens to chose from. I love my wife and miss our intimacy very much. I will only address the other two questions. First, this is the time when you need to have a frank conversation with your wife.
Many women enjoy penetration during sex, and many women enjoy sex without any penetration.
She may be happy to have other contact with you, including oral sex, manual stimulation with your fingers, and more extended full-body contact. If she says she misses penetration, then you have several options. Some women like the feeling of thrusting, others like the feeling of just being filled up. Having something in the vagina during orgasm can increase the orgasm's intensity, but many women will say it's not necessary. If you wife says she misses actual intercourse, then you can purchase a harness and dildo and penetrate her as you used to.