A Morkel although is he also not test quality himself & shouldn't be near the SA test set-up either. Would certainly offer more to any team he is in compared to Tsotsobe for sure.
Tsotsobe competiton for a place in the test squad are De Wet, Alexander, Parnell, McClaren, O'Reilly (maybe others i dont know of also). They all should always be ahead of him in the pecking order.
I usually just browse the forums, but your assertion of who is competing with who for test places is a bit off. Firstly, Tsotsobe is actually a very, very good first-class bowler. His call-up was very much deserved when it happened. You can't really judge his position there on a 20/20 tournament, when the format isn't his best. He also came off a serious injury towards the end of last season and still needs to get back to full fitness.
Craig Alexander has only just started playing after an exceptionally long lay-off. Add to that first-class stats of 96 wickets @ 33.03 and you have somebody who has a lot of potential, a lot of talent, but not somebody who is ready to play international cricket.
Parnell - fair enough, he's played test cricket and is a great talent, but even his debut was slightly premature. He has yet to take a first-class 5fer and more experience would serve him well, although it's looking likely that he'll be blooded at international level rather than franchise level:P
Ethan O'Reilly has raw talent, yes, but he hasn't even played a four-day match OR an MTN40 for the Lions, and you're here talking about test cricket?
To be honest, if you were being fair to the consistent bowlers in South Africa's domestic system and ignoring whatever biases the national selectors seem to have, here are the options:
Vernon Philander (don't laugh) - 200 wickets @ 20.54 (exceptionally skillful with the new ball)
Quinton Friend - 197 wickets @ 23.61
Rusty Theron - 131 wickets @ 22.85 (NOT a 20/20 specialist)
You could add Friedel de Wet to that list too. Johann Louw also had an exceptional first-class season last year but he's getting on now.