if you want to be safe, buy the SME 3012 and you can use many cartridges on it.Or the Orotofn RMG 309(my favorite!)To go for the arm for "A" type SPU you have to be more dedicated or have two arms deck....then you can use any of the "G" type cartridges.
AND if you really want to use "A" cartridges, there is an adaptor(AP J1) for the "G" arm to use "A" cartridge.....simple!
AND if you really want to use "A" cartridges, there is an adaptor(AP J1) for the "G" arm to use "A" cartridge.....simple!