Well basically, you get 3 different types of mounts. Hs33 mounts, which are two paralell threads, V-Brake mounts, which is a single thread and disc mounts which is again, two threaded mounts.
Instead of replacing V-Brakes with hs33's I would suggest BUYING a frame with Hs33 mounts already, as it will be only a tiny bit more expensive, and you will not have the hassle of V-Brake to hs33 converters. It is also hard to setup hs33's with V-brake converters, especially for a starter like you.
HS33 Mounts:
Disc Mounts:
V-Brake Mounts:
I PERSONALLY would recomend the onza comp and if I was you, I would buy this bike. It is cheap, has the double hs33 setup which Ive already told you about and looks pretty nice too.
As you can see from the pictures, Hs33's constist of 4 threaded wholes in the frame. Each "Clamp" has 2 bolts which screw into the frame, and becareful when doing this as you can cross thread easily and have to buy a brand new frame instantly. The V-Brake only has 2 bolts, one on each side of the frame meaning the brake cannot hold aswel or be as powerful inless setup correctly on the same rim. I will not go into detail about double disc inless requested.
EXAMPLE- My friend made a bad mistake which I don't want people like you to make. He bought a saracen trials bike which is alright for starters. It had V-Brake mounts on the forks and frame, but the rest of the bike was stock. As he got better he decided to upgrade to hs33's but then realised the costs. He needed x2 Hs33's costing £120 x1 Frame costing £200+. If he had have bought a frame or bike which came with hs33's or Hs33 mounts then he would not have this extra cost, which would work out to be more than simply buying the correct bike in the first place.
Take a look around and see what you like, and tell me if you want and I can give you feedback on whats what.
By the way, I would not recomend buying anything over £650, and when you pay that sort of money for a starter bike, you might aswel have a ZOO! Lynx or a Echo Lite!!!
THE BIKE I RECOMEND: