Your budget is pretty reasonable.
If you want the best 4 season clothes, look at the hein gerike master V suit. You will always compromise in the very hot weather or very cold weather in 4 season stuff but this is the best I've found. In the recent weather of 2 degrees in the morning, it keeps me perfectly warm with just a t-shirt. In summer, sans lining, it does get a little warm due to lack of vents. It's still pretty good. Waterproofing is excellent and has a 5 year warranty. It's steep - perhaps try the jacket (most exposed) paired with a cheaper pair of trousers and see if it's worth it.
Hivi stuff - get a cheap fluorescent jacket and shove it over the top. Has the added advantage of stopping rain hitting your jacket as hard so improving your waterproofing and stopping more of the wind. Other advantage is that there are times you don't want to be dayglo. I use a hivi for commuting and bad weather, the rest of the time just my normal jacket.
As for looking like a cop - I sort of do at first glance as my helmet is black and white but since I started using the hivi, people have got out of my way a lot more when filtering and have actually seen me coming. It becomes pretty obvious that you're not a cop very quickly but that 1 second of uncertainty might make people think a little harder before taking a chance.
If you really want a cop one, there is an e-bay seller selling surplus with the tags removed. Just search for police hivi or something. Beware that whilst you can get away with a white helmet and a hivi and just say "I want to be seen", wearing a cop jacket is definitely walting and shoving blue labels back on there could be classed as officially walting and land you in a lot of trouble.