A common methodology for development of your wedding ceremony is "mix-and-match".
The celebrant (officiant) may offer you several "standard" ceremonies, but give you the option of taking parts from different ceremonies to make your own "unique" ceremony.
Or, your celebrant may off you a "resource pack" consisting of a number of choices for introductions, vows, ring exchanges, readings and so on.
While both methods may be quite efficient for the celebrant, and will give you the illusion of choice, are you really going to end up with a unique ceremony that accurately reflects who you are as a couple and your commitment to your marriage.
The answer is no.
What you will end up with is a fairly generic ceremony, perhaps "personalised" with a short introduction recounting how you met, but, in truth, it will be a ceremony that could be identical to that of another couple that made the same choices from the same limited options.
And, if those choices are made from the second option - the resource pack - it may well be that the ceremony, style-wise, is quite disjointed.
And, inadvertently, if the choices offered by the celebrant include material harvested from other sources, you may be participating in an illegal act - infringement of copyright.
But there is an even more important issue.
Your wedding ceremony is a blueprint for your marriage. The vows you exchange communicate to each other, and to your family and friends present, what you are committing to, and the sort of relationship your marriage will be. So your vows should be specific commitments negotiated through the development of your ceremony using a mindful process.
Ask any celebrant you are considering asking to officiate at your wedding what process he/she uses to ensure that ceremony is consistent with the negotiation and learning that results from your participation in pre-marriage relationship education.