I totally agree.
Using a modular system has the advantage that you can call your high-cap .45 anything you like, whether it's a M1911A1, or a S&W 99 or something else.
The more we talk about this the more I think a page of "example/iconic" builds would be a definite plus - for example a Walther PPK would be .32ACP + Pistol + Compact (bonus to concealibility, subtracts from magazine size)
You're always gonna have the guy who wants his DEagle (.50, Pistol, Rugged) and the guy who wants his Steyr TMP (9mm, Pistol, Auto Fire, Extended Mag), and so on. But you will (IMO) also get the guy who wants "a sidearm" (9mm, Pistol). Which the GM could define as a Browning High Power, Glock 17, SIG Sauer 220, or simply leave it as "a pistol"