It really depends on what level of performance you're after. For plinking loads, any number of powders can be used. Putting a little more flare on the casemouth may help your seating problem. You might also want to check the diameter of the expander to make sure it is not undersized. The LaserCast bullets are typically sized .356" for 9mm.
For higher performing JHP loads, it will also depend on the performance you want. For 115 and 124 gr. JHPs, HS-6 is very good. For best performance with 147 gr. JHPs: AA#7. If you want highest velocity with minimum flash for a defense type load, or one to replicate your factory carry load, I've used V-V 3N37 for about 15 years for all three common defense weights. Vectan SP-2 when it was available. The powder I am using now is very much like 3N37, cost less and has very low muzzle flash: Ramshot Silhouette. Similar in burn rate to WSF, HS-6, 3N37 and Power Pistol.
People tend to have different opinions about the performance a powder is capable of. I don't advocate this except for those who are very experienced handloaders who have 9mm pistols that are capable of firing 9mm with very long OACLs, but among the guys that load mostly 115 and 124 gr. JHPs for 9mm Major Competition ( 165 PF: 1331 FPS with a 124 gr. JHP from 5' barrels ) with mostly 1911s that allow the very long lengths exceeding the 1.169" spec, you'll see about five powders used most often. HS-6, V-V 3N37, Ramshot True Blue and Ramshot Silhouette is fast becoming a favorite. Longshot is used by some guys, but at higher pressure it gets very loud.
For a load that will duplicate the performance of a very good defense load like the SPEER 124 gr. +P Gold Dot, Silhouette is excellent.
