It's been some time since I did it, and I will admit to being quite scared of what I would see, but I don't regret it. It was a very sudden and unexpected death and having some time to sit with them and hold their hand, whilst it was upsetting at the time, ultimately helped me to come to terms with the loss and move on from the state of complete shock I was in. I remember being surprised at how different their hand felt in mine compared to when they were alive, and I knew that life was gone.
It was quite a strange experience but not traumatic. They were still the person I loved but by seeing and touching them myself I could see that they had moved on. Prior to this I found the thought of cremation absolutely horrific, how could anyone think of doing this to him ? But it took that fear away, the spirit or soul or life force (as you prefer) had already flown free.
I think that in the UK we have in many ways separated ourselves from death, in earlier times it would most likely be the family who washed and laid out their loved one after a loss, so now we don't know what to expect from the reality of death and we are fearful of all it entails, especially when it comes to the physical body.
If you are in two minds I would suggest calling the funeral home and asking them any questions you have about how your father will be laid out, about how he will look, even about the room and how much time you can have. They have seen grief in so many forms, you need not fear any judgement.
You must do what is best for you. I do think that there is some truth in the saying that funerals are not for the dead, but for those who are left behind and I think the same applies to your decision. Your obviously loved your Dad very much and I'm sure he would want you to do whatever brings you greater peace.
Apologies for the essay OP, I'm so very sorry for your loss, please look after yourself. X