They are not cheap and not perfect, but the best solution for gear over professional clothing is the tried and true Aerostich Roadcrafter. I have the two-piece which works just as well as the 1 piece.
Pros:
1. Can be worn over everything and will still be comfortable. Clothes won't wrinkle underneath and if folks don't see you with the gear on, they'll never know you rode in. Can let you still look very professional.
2. Goretex means it's actually, really waterproof. This is important because weather can be different for the ride home.
3. Crash protection is very good, and the suit can be repaired.
4. Simple venting works very well - to a point
5. Can be custom made for odd sizes. My legs are really long, so I had the pants lengthened
6. Will last a very long time - I have had my suit for about 10 years
7. Holds its value - check ADVrider in their used gear section - old Aerostich suits still sell well.
CONS
1. Very expensive, all things considered. But the gear has a great pedigree, a cult following and a tried and tested manufacturing process. Amortized over 10 years (and I expect to get another 10 out of them) my Aerostich is actually the cheapest gear I've ever bought
2. Not made by child labour
3. Not great in weather over 28C.
4. Kind of ugly, if you care about that sort of thing
5. Unless you ride to the factory to get measured (the ride to Duluth MN is beautiful though) the process of customization can be a bit of a *****, and shipping is expensive unless you can ship it to a US address.