Henrick, I thought about doing similar mods with a Squier a few years ago. I liked the sound of the Squier, but wanted a the guitar to stay in tune and play a little better. When I looked at replacing the tuners, bridge and pickups, I decided that I could do better by buying a guitar that already had the mods, so I traded the Squier on an American Standard Strat. I liked both guitars, but when it came down to it, neither guitar was really what I wanted. I sold the Strat when I reduced my guitar inventory and continued to play my Les Paul. I looked occasionally for another Strat, but didn't find anything that really knocked me out until I found an American Deluxe Strat early this year. This guitar plays and sounds exactly like I want.
By the time you change the pickups, hardware and neck - your guitar will play and sound totally different. The custom paint may change the sound, depending upon the thickness and type of paint. The pickguard and knobs shouldn't change the sound. In addition, the Floyd Rose may require the body to be routed for proper fit. You might consider keeping your original Squier stock and buying another to hot rod.
All that being said, if you decide to mod a Squier - pickups run from around $50 to $80 each, pickguards from $15 to $40, a set of knobs is about $7 and you can find a Floyd Rose Pro (gold, of course) for about $180. If you install a Floyd Rose, you will probably want to install locking tuners and an LSR roller nut. You may have problems finding a neck with maple fretboard - Fender's official policy is that they will not sell necks except to replace "certified" damaged necks. You may be able to find one at a local dealer. If there is a Guitar Center in your area, you can find a lot of the parts there.
