I don't think Gehmann make pellets, they make a pellet sorting tray which you may have seen, match pellets are best tested to find what is compatible with your gun, pistols basically any good match pellet, RWS or H&N, the pistol target is not so critical on group size, rifle is best to test and find what is best in your rifle as the ten is only 0.5mm so group size is quite important. That said I presume you are only just starting so inless you can hold the ten use the same criteria of using any good make, i.e RWS or H&N.
Rutty is right with the boots, and further you need moving room for the toes in shooting boots for best ballance so get a size with a good cm clearance at the front for the toes, they are for standing still not walking so fit is important for that alone, need to be a firm fit around the foot and ankle but have plenty of space for the toes, most people go up a size to achieve that. Some makes are a bit different on sizing, Kustermanns can be a bit tight to the size, Kurt Thunes often a bit big to the size. Hope thats not confused you too much!
Good shooting
Robin
Walther KK500 Alutec expert special - Barnard .223 "wilde" in a Walther KK500 Alutec stock, mmm...tasty!! - Keppeler 6 mmBR with Walther grip and wood! I may be a Walther-phile?