Croon - I'll try and demystify things a little ...
Top and tail bowls are for daily washes and/or nappy changes if you choose to use water and cotton wool instead of wipes (or at times of soreness). You could just use Tupperware or cereal bowls.
Baths are useful as it's a waste to fill an adult bath to 2-3 inches. Also, you can put a baby bath on the floor in the bathroom or in front of a radiator to save you leaving over the bath. Again, not essential but useful. You could equally just put baby in your bath and have a soak/cuddle together.
Bath supports are more useful as try get older. The hard plastic ones are for nearly sitting babies (so 4/5 months plus). There are some that look like bouncy chairs - sort of towelling martial stretched over a frame. These are useful from about 6-8 weeks, once baby can hold their head better. Useful if you're bathing baby alone. As you can use both hands. Very useful if baby has hair that needs washing (either due to amount or cradle cap etc).
This stuff is great to pickup second hand as it's easy to clean and you don't need it for long. I know some people like to have everything new though.
Hope everyone is well. I've not posted much here recently as I'm feeling a bit anxious and fb seems safer somehow. I'll feel better once we've had our scan (Monday!) and hopefully will know more about my maternity leave and how my job might change over the coming months soon, and I think that will help.