I'm gonna stand behind Melnie and nod lots!...
NIKWAX are the biz...Waterprofed a jacket with it years ago and that was in spray form.
I use NIKWAX protector on my leathers too...Does the job...
Got it from Gericke...You can get most NIKWAX stuff from there.
AND why you need waterproofs no idea...? I'd have thought you were that fast that you would have whizzed in and out of the drops after what I saw at Cadwell!
:P