I am not scared to travel just I would like something more confortable, I mean without going to Krakow and then come back to Zabierzów or by train without change 2 or 3 times and using 2h30m or worse 4h40m.
Direct trains from Katowice to Kraków stops next to Business Park, but they take ab. 2 hours. I don't know if you checked it accurately, but you should look here: rozklad.sitkol.pl - or here full timetable ("tabela 140"): - but only in Polish (remember that it changes since 2nd September). As far as I can see, you have convenient trains for working from 7.30 to 16.00, but not from 9.00 to 18.30 (anyway it would be terrible to wake up at 4.00 AM) . Trains are slower than buses on this route - bus to Kraków centre takes, as the people before me mentioned, about 80 minutes - using the A4 highway. From Kraków centre to Business Park you have about 15-20 minutes by train. This is your choose, if you want to get there faster, but through Kraków centre, changing vehicle there, or slower, but directly.
I agree that best would be to live in the middle between Kraków and Katowice. To go from Katowice to Kraków by car... for my calculations, it would be about 1500 PLN a month.
Ticket from Katowice to Kraków for a bus is 14 PLN, so for month it would be 560 PLN. From Kraków centre to Business Park 4 PLN, or you can buy one cheaper ticket for a month for 100 PLN. Together - 660 PLN.
By direct train from Katowice to Business Park - 15,60 PLN for one ticket, 290 PLN for one ticket for a month. So much cheaper.
What is more - it is also possible to buy cheaper train ticket for a week - but less cheaper than buying one for a month. From Katowice to Kraków Business Park - 110 PLN for a week.