Some mates and I wear Alpinestar jonny suits (£120 or so) over the leathers when we do west coast Scotland trips and have to say they work brilliantly. Wore them on the track day last week for the first couple of sessions and for me the way to go as you still look FaF....which it is impossible to do in a touring suit.
Scott waterproof jacket and trousers, stretch and breathable https://www.motolegends.com/motorcycle-accessories/scott-ergo-pro-dp-rain-jacket-yellow.html
I see you are going in textiles, so no waterproofing issues, a bit of info to all though, although in general any medium plus quality leather offers far more accident protection than just about all textiles except BKS and Hideout leathers(textile). BUT like Sampson having his hair cut off, once leather is wet it looses its magical protection. A cheap over suit is a good compromise.
I was a London courier when the first silver Rukka came out, very sweaty with full leathers underneath!!
One piece oversuits are too much of a faff, I remember doing the silly dance under bridges or trees trying to get into a Frank Thomas aquapak. Now I always use good quality two piece hiking waterproofs over my leathers, they are light and fold up small.
Gore-Tex Pro is your friend here because the water wicks off it and isn't retained in the garment. I commuted ~15k a year and even if caught in a monsoon they were always dry (on the inside) when next used. Chuffing expensive mind. Main thing with leather(s) getting wet is to never force dry them with heat... and as others have said feeding them once dry is the way to go.
BMW (bad word I know ) did a hydrophobic leather 2 piece suit called the Atlantis. I'm not sure anyone else has tried to replicate this. I tend to ride in textiles, but if I decided to tour in the leathers I would probably pickup a 2 piece set of goretex outer shells.
Unless they're not there this year (I'm not so can't check) Scott usually have a stand behind the grandstand and some TT special offers on. RST the same.
+1 on one-piece faffery. The aforementioned Ducati jobs are pretty good too. Made by Spidi and not bad value. You can get them in high vis or black with reflective snazzy bits.
That’s why you take a carrier bag and put it over your boot when you put the over trousers on. Makes it a doddle.
I have BMW Atlantis clobber, and it’s brilliant: 100% waterproof yet considerably comfier and more breathable than Gore-Tex. It’s my most versatile – and most worn – motorcycle clothing. BMW has just rebranded the Atlantis as Furka. It’s pricey, but you’re worth it
I think I preferred the original name, but the Furka pass is often wet so it's probably a fair name. It's no more expensive than the high end textile suits by the likes of Rukka and Klim and it's nice they've resisted the urge to write BMW over the back in really big letters like some brands do.
