Cheema is the victim of the cold, very conservative Management Period (Captain, Selectors, Board) of Pakistan cricket. At official 32, he is clocking constantly over 140+KM in UAE desert & one of the Bangladeshi batsmen told me that Aizaz seems to hit the bat, rather than other way round, after pitching even on these dead slow Mirpur tracks. He can swing the ball & I am sure, from his slingy action, he was clocking over 150KM occasionally, when he was 23. Still his average pace is better than most other Fast bowlers, even excluding deliberate slowers.
Inzi, the great player that he had been, was one of the most defensive & loyalist (I don't think he was biased) person as a captain - didn't allow many new comers. Since Imran he was probably the most powerful Captain, but used to rely on his own group & may be from his re-identified Islamic beliefs (Well, I have senior pals, who knew Inzi since '91-'92), had a preference of players, for their off the field life style. I think Butt was the only youngster during a period of '03-'07, that made into the Pak team regularly, whereas Pak won 2004 & 06 U-19 WC during these period & hardly any (or none) of those boys made it during Inzi's time.
Still, I think, Sami is the Fastest bowler in contemporary bowlers, purely for pace. I am sure, Rauf was much faster to have that sort of FC record in his 20s, Cheema was definitely FAST, there was another guy (Fahad Mashud, I guess) - the keeper was jumping to glove this lifters, still rising on dead tracks, I think Irshad was as fast as any one & there must be few others who can clock 150 KM occasionally, even on dead surface. Even, I have seen Mashrafee clocking 147KM; but yes, 155+ KM are different breed, born once in a generation.
I don't think ever there 'll be any short of Fast bowlers in Pakistan. Pace bowling is just not about what the Speed Gun telling, there is shoulder & wrist in it as well. If you bowl Fast, you 'll go for runs & unfortunately, in last few years, for the depth (or lack of it) of batting, every Pak Captain was very defensive to concede easy boundaries & I felt bowlers were instructed not to unleash pace. Also, I feel Aaquib is a very good bowling coach, but he is more of an English Condition Coach - line, length & discipline - 'll not encourage tearaway, but wayward raw pace. I watched Waquar being hammered away by Aussie batsmen in '89-'90 WSC, but Imran was pushing him for more pace. Within six months he got the control & went to Sharjha in April '90 & then to Surrey.
There is a fundamental difference between Pak Fast bowlers & Aussie or Proteus fast blowers - they bowl in different length. For the hard & scratchy tracks, Southern hemisphere fast bowlers try to hit the deck, while the Pak bowlers try to beat in air for the sort of horrible tracks they play. No one can bowl better, faster & lethal than Pak bowlers with the old ball, but since WW, I have seen Pak bowlers struggling to bowl Fast with the new ball. By the way, how Fast is is the current U-19 bowlers?
One decent series and suddenly they're all the best bowlers in the world. 
was sidelined by 
and was only picked against minnows what an insult to the great man, but then again it was the emergence of another great fast bowler 
career.
's batting S/R of 110 in ODI's 
.I have heard a lot of good things about u19 pacer zia ul haq i have high hopes from him
