Not sure if any of my response will help but we just got our daughter christened on 23 Nov.
Firstly, I am Catholic and hubby is C of E, baby and I go every week to mass at the Catholic church since she was 8 weeks, so the priest has seen her grow. We have yet to be married in a Catholic church, will do so when baby can be a flower girl, just so she participates. But it wasn't a problem for baby to be christened.
Since I was the only Catholic, my family is abroad, we asked a fellow parishioner to be a proxy godparent. She has 2 godmothers and 1 godfather. The ceremony was after the Sunday mass, lasted about 1/2 hour, no hymns, but all the same a very nice ceremony. We all thought baby was going to answer the priest at some point in the ceremony. She wore an heirloom gown, last worn 21 years ago and I think grandpa wore it as well, very adorable. At 3 am I remembered the priest asked that she have something that he could cloak her in during the ceremony that symbolized the presence of God, so I just cut a large square of fleece like a blanket and we wrapped her in that. The morning was only chilly and not cold, so perfect for her.
Having the ceremony on our anniversary was one way of gathering family and friends together. We held the reception at auntie's house instead of a restaurant (sit down meal). We wanted everyone to mingle and not be confined.
I designed the invitations, made the christening cake - yummy fruitcake, made christening favours which went down extremely well, many commented that was the first time they had ever gotten a gift upon leaving such an occasion. I think the favour for guests is a very nice personal touch to the event. We did the catering ourselves, and it was a good spread and well complimented. Lots of foods were left over and some forgot to put out. What was very different was toasting baby, we gave her toasts using Sangria as we weren't keen on champagne, although wine flowed freely previously.
I am now in the procees of designing the thank you cards for the lovely gifts she received, she needs a jewellery box now. I don't feel really pushed since guests were presented with a lovely favour, sort of buys me more time.
I think you should plan your event the way you would expect to feel as if you went to a christening yourself. Keep within a budget and time does past quickly. Our reception lasted 5 hours and everyone enjoyed it. Many of the guests weren't church goers but 33 of the 35 guests made the effort to go to church, I was completely impressed by it.
With the success of this, we hope to plan more events as practice makes perfect. Designing the invitations and favours were fantastic and personal. Can't be duplicated. That's is enough rambling, if you have queries regarding church matters the best person to speak with is the religious official, he is the most important one besides baby after all.