Racing leathers would be overkill, decent boots wouldn't be and wouldn't even be seen if you wore jeans over the top of them.
The minimum kit I'd be wearing is:
£100 on boots, RST Tractech for example
£100-£150 on kevlar jeans.
£80-£150 on a leather or textile jacket
£30-50 on gloves
£90-100 back armour/protector
£100 on lid.
So you can kit yourself up well for just over £500. It's not so much the speed you're going to be doing but the speed somebody else is going to hit you. Coming off at 30/40 mph is a relatively low speed crash in a car but on a bike it can be fatal. You never know what you're going to slide in to (kerb, road signs, ditches) or slide under (cars/lorries). Remember your body has NO crumple zones except bones that break and limbs that can be crushed.
If you've got a new bike(?) it seems a bit odd to be hunting for very cheap bargains. I understand top of the range is overkill as you stated and as mentioned expensive isn't always better as proven with Sharp testing on lids.
This gear is going to potentially save your life so you want to know it's up to the task.