Since you and your significant other were never married, you can't hold title as community property with or without right of survivorship because only legally married people can acquire community property. There is no such thing as vesting as joint tenants without right of survivorship as the right of survivorship is one of the built-in characteristics of joint tenancy. If you are not married, you will hold title either as joint tenants (with right of survivorship) or as tenants in common (unless you create a trust and hold property as trustees of the trust). In your case, because you are not married, you would be deemed tenants in common because your failed community property vesting does not turn into a joint tenancy (without the community property part). Similarly, when spouses who hold title as community property with right of survivorship get a divorce and the divorce becomes final but they don't change how they hold title, the right of survivorship is severed by operation of law upon the effective date of the dissolution judgment.
If you opt for the joint tenancy vesting method, each of you own one half undivided property interest. The right of survivorship aspect does not become relevant until one of the joint tenants dies as the one-half of the deceased joint tenant automatically passes to the surviving joint tenant, meaning that the surviving property owner becomes the sole owner of the whole property. The upside of joint tenancy is that the real estate does not become part of the deceased property owner's estate and does not have to go through probate. The downside is that neither joint tenant can dispose of his or her share in a will. In other words, neither of you could give an interest in the home to your children or any other third party without first severing the joint tenancy. If you do not want your significant other to end up with sole ownership of the home should you predecease her (or she does not want you to become the sole owner of the property should she predecease you), then joint tenancy is not for you and you will want to go with tenancy in common.
Tenants in common can either own equal shares or unequal shares (with joint tenancy, all joint tenants own equal shares = if there are 2 joint tenants, each owns one-half, if there are three joint tenants, each owns 1/3...). As long as you are both alive, there is really no difference between joint tenancy and tenancy in common if you choose to own equal shares. If you choose tenants in common, either of you can leave his/her one-half interest to someone other than the other property owner. The upside to holding property as tenants in common is that it gives you more flexibility. The downside is that in the event of the death of one of the property owners, the deceased owner's interest in the property has to go through probate (even if there is a will leaving the one-half interest to the other property owner).
If you choose joint tenancy now and you later change your mind, either of you can unilaterally sever the joint tenancy by transferring their one-half interest to him/herself as tenant in common. The consent of the other joint tenant is not required to sever joint tenancy.
If you want to avoid probate, but don't want to hold as joint tenants, you may want to consider setting up a (revocable) trust and hold title as trustees of the trust.
I would recommend that you consult with an estate planning attorney and also have an attorney prepare the new deed to make sure the vesting is done properly this time.