I have owned a SP01 and I have a collection of sigs.
If I had to chose one in 9mm, I don't know if I could. I like different things about both pistols.
The CZ75 are excellent pistols, very good quality and performance for the $$$.
Others have mentioned the benefits and cons of each, one benefit that I will add for the CZ > Sig is the lower slide profile makes it easier to get a high grip/bore. This makes the pistol more instinctive to point and shoot accurately as well as control in my experience, hence why I really like glocks as well. The CZ have excellent triggers from factory and I really enjoy shooting them.
The Sigs are very nice pistols, I don't find the American made ones as bad as others here claim... and I own several genuine German made Sigs. German made sigs definitely have better fit and finish and I find the decocker/trigger smoother than American strait from factory pistols (including the elite), but I have never had any FTF/FTE from any of my sigs, and I find the accuracy is about par on all of them.
I do prefer the sig controls to the CZ, and I do find the Sig more comfortable in the hand. The sigs do have a very high slide profile compared to the CZ, and for speed drills I did find I was faster with a CZ for that reason. The Sigs do have a lot more options for accessories and parts though, with a substantial aftermarket industry and excellent mastershop services available... although I would say that the SP01 Shadow is on par with a tuned sig elite, perhaps better than most of the Sig line (226R- Elite) in terms of accuracy and performance.
Just my .02
If money is a factor save a few hundred and get the CZ75/holster and ammo as you will still come in under the price of a used Sig. If you are wanting night sights and more holster options... or you just like sigs, keep your eyes to the EE and you can probably land a nice used pistol with holster and mags for under $1k. Personally for sigs I like the non railed 226, (I like the look and feel) these tend to be a lot cheaper and with a few $$ in springs you can keep them tuned up nicely yourself. For $60 Questar you can get new springs and a SRT, keeping your pistol going for years.
Cheers
Cheers