HG do (did, when I bought them) decent waterproof oversuits.
2 piece/1 piece: your choice.
2 piece can be worn as a jacket if you really want and if one bit gets damaged you needn't replace the lot.
a 1 piece lacks the gap in the middle that wind could push rain threw... and they are a bit cheaper.
Buy bigger than expected: you don't want it too tight when you're riding and the spacier the easier to into when wearing all your clobber.
Look for a nice zip that has a wide, doubled-over flap alone its length then fastened with velcro or frequently spaced poppers: by riding a bike you are effectively throwing yourself at the rain, increasing the chance of water ingress...
Get kit that has some sort of lining, like that faux-satin stuff. It makes sliding it over jackets easier.
Another tip is stick a plastic shopping bag over your boot before you try and slip into trousers: the boot slides easily through the leg, rather than having the sole and inflexible boot snagging inside the trouser leg. Then whip the bag off and repeat with the other boot!!
Adventure: it's an experience, not a style!
(so ride what you like, but ride it somewhere new!)