I have a budget of £200 for the wheelset, do you have a suggestion of of exactly what I could go for?
First, you need to decide which tyre size(s) you think you would like to use -- e.g., 700x25.
Then, you need to decide if you want to re-lace the existing hubs with the 700c rims or if you want to try to find some excess inventory which is being sold (as on eBay.UK).
While pre-built wheels with 700c rims & disc hubs were rare 8+ years ago, they are quite common now -- I am presuming that your Bad Boy uses disc brakes -- if you are patient-or-lucky, you may be able to find a suitable wheelset on eBay.UK for about £100+.
If you are going to re-lace your current hubs, then it may cost £125 just for the rims & spokes AND presumes that it is a DIY project -- as a last resort, you could always bring the laced wheels to a bike shop to have them true the wheels.
To more-or-less repeat:
- A 622-13 rim is only for really only for 700x19 & 700x23 tyres ... I have as many wheelsets with this width tyre because I was deluding myself into thinking that I wanted to maintain rim-width continuity with the tubular rims & sew-up tyres which I pretty much stopped using.
- A 622-15 rim seems to have become the de facto standard due to the widespread popularity of the MAVIC Open Pro rim, at least, in North America.
- A 622-17 rim would be a good all-around rim size ... but, they are not as common as they once were and may be difficult to find although I think ALEX may have a rim in that size ... it's probably the best size is you know you are going to use either 700x28 or 700x32 tyres.
- A 622-19 rim seems really wide when I look at it ... it is probably best for 700x42 & wider.
There are other rim sizes. My recollection is that the Ambrosio clincher rims are 622-14.
Anyway, check eBay.UK for a 700c wheelset that is laced on disc hubs.
If your Bad Boy frame doesn't have disc brakes, then it is actually pretty easy ... you just need to measure the distance between the "fender" mounting hole that is in the top of the fork AND on the rear stays near the seat tube ... and then, buy the appropriate TEKTRO Road brake caliper (again, let eBay.UK be your friend).
Using Road brake calipers with 700c wheels should not be eschewed as an idea even if your frame has disc brakes. Here's a picture of one of my old Hardtail frames in which I have 700c wheels:

BTW. Changing your Bad Boy's FLAT handlebars for DROP handlebars will go a long way toward making you-and-your-bike faster because you will be lessening your wind resistance if you are riding in a less upright position ... but, think of the Drop bars as being a future consideration ...
- Non-Xenon-based 10-speed Campagnolo shifters (pictured above) will index with most Shimano MTB rear derailleurs.