1st CSL buy HELP

[Marchino]

Hello

I am intersted in buying my first CSL - I currently own an E92 DCT - and I need your informed help.

I have seen several CSL's and my focus is now on this one:
http://www.pistonheads.com/sales/3620523.htm

I inspected the car and talked to the current owner who seems a specialist in BMW M cars. I am very impressed by the car.
My only concern is the real road useability of a modified CSL (KW suspension kit, Alcon Cup brake kit and Milltek exhausts) and, more importantly, the residual value the day I want to sell it.

Do you think the above mods will decrease the value of the car vs a fully original one?
Do you think this would be a good choice is i want to use it as week end car + 3-4 track days a year? or should I look more at an original one?

Also, do you have any additional information (previous owners, track days etc..)you want to share about this car (Reg M60 CSL)?

any help would be highly appreciated

many thanks for your attention