Huddy im about to install cams on my RB20 set up and have looked into it a fair bit the last few weeks.
You would be waisting your money with 256 cams and also cam gears in my opinion. You want to be matching the cams with your set up and also what your goals are with the engine eg: are you wanting to make more top end or quicker response???
With the 24 and your turbo then i would be looking at either 264 or 270 cams. When it comes to upgrading your springs (can be costly) again it depends on the lift of the cams you go with and how much boost you are going to be running and the health of the stockers.
I've been told that the stock springs will be ok upto 9.1lift but anything over that then you would have to replace.
Price wise has been a little varied with the quotes i've got so far, and then when i think i have found a bargain i seem to get stooged
Interested to see your results
GMB